remove experimental child aggregates

[DavidBadura]

We removed our experimental feature of child aggregates.
This was our first attempt to split aggregates into smaller parts,
but we found a better way to do this with the Micro Aggregate feature.

[github-actions]

Hello 👋

here is the most recent benchmark result:

SplitStreamBench
================

+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                         | time (kde mode)                                     | memory                                     |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                 | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad10000Events () | 4.370ms (±0.00%)   | 4.280ms (±0.00%)   | +2.10%    | 37.651mb        | 38.184mb   | -1.40%      |
| benchSave10000Events () | 336.720ms (±0.00%) | 343.010ms (±0.00%) | -1.83%    | 37.723mb        | 38.257mb   | -1.40%      |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SimpleSetupStreamStoreBench
===========================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 1.009ms (±0.00%)   | 1.017ms (±0.00%)   | -0.81%    | 34.458mb        | 34.458mb   | 0.00%       |
| benchLoad10000Events ()                | 56.134ms (±0.00%)  | 56.447ms (±0.00%)  | -0.55%    | 34.458mb        | 34.458mb   | 0.00%       |
| benchSave1Event ()                     | 1.138ms (±0.00%)   | 1.264ms (±0.00%)   | -9.92%    | 34.458mb        | 34.458mb   | 0.00%       |
| benchSave10000Events ()                | 283.695ms (±0.00%) | 283.876ms (±0.00%) | -0.06%    | 34.458mb        | 34.458mb   | 0.00%       |
| benchSave10000Aggregates ()            | 8.549s (±0.00%)    | 8.383s (±0.00%)    | +1.99%    | 34.458mb        | 34.458mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 5.106s (±0.00%)    | 5.128s (±0.00%)    | -0.42%    | 34.458mb        | 34.458mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SubscriptionEngineBench
=======================

+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
|                           | time (kde mode)                               | memory                                     |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
| subject                   | Tag: <current>  | Tag: base       | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
| benchHandle10000Events () | 3.191s (±0.00%) | 3.194s (±0.00%) | -0.08%    | 46.961mb        | 46.961mb   | 0.00%       |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+

SimpleSetupBench
================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 968.700μs (±0.00%) | 974.200μs (±0.00%) | -0.56%    | 34.344mb        | 34.344mb   | 0.00%       |
| benchLoad10000Events ()                | 51.444ms (±0.00%)  | 52.249ms (±0.00%)  | -1.54%    | 34.344mb        | 34.344mb   | 0.00%       |
| benchSave1Event ()                     | 1.053ms (±0.00%)   | 978.200μs (±0.00%) | +7.67%    | 34.344mb        | 34.344mb   | 0.00%       |
| benchSave10000Events ()                | 216.115ms (±0.00%) | 218.501ms (±0.00%) | -1.09%    | 34.345mb        | 34.344mb   | +0.00%      |
| benchSave10000Aggregates ()            | 8.496s (±0.00%)    | 8.249s (±0.00%)    | +3.00%    | 34.344mb        | 34.344mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 4.902s (±0.00%)    | 4.911s (±0.00%)    | -0.17%    | 34.344mb        | 34.344mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SubscriptionEngineBatchBench
============================

+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
|                           | time (kde mode)                                   | memory                                     |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
| subject                   | Tag: <current>    | Tag: base         | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
| benchHandle10000Events () | 77.513ms (±0.00%) | 77.043ms (±0.00%) | +0.61%    | 34.813mb        | 34.813mb   | 0.00%       |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+

SnapshotsBench
==============

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad10000EventsMissingSnapshot () | 51.754ms (±0.00%)  | 51.741ms (±0.00%)  | +0.03%    | 34.418mb        | 34.418mb   | 0.00%       |
| benchLoad10000Events ()                | 918.400μs (±0.00%) | 893.800μs (±0.00%) | +2.75%    | 34.418mb        | 34.418mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

PersonalDataBench
=================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 934.300μs (±0.00%) | 897.500μs (±0.00%) | +4.10%    | 35.548mb        | 35.548mb   | 0.00%       |
| benchLoad10000Events ()                | 97.880ms (±0.00%)  | 98.693ms (±0.00%)  | -0.82%    | 35.548mb        | 35.548mb   | 0.00%       |
| benchSave1Event ()                     | 1.465ms (±0.00%)   | 1.585ms (±0.00%)   | -7.55%    | 35.548mb        | 35.548mb   | 0.00%       |
| benchSave10000Events ()                | 254.649ms (±0.00%) | 257.462ms (±0.00%) | -1.09%    | 35.550mb        | 35.550mb   | 0.00%       |
| benchSave10000Aggregates ()            | 12.598s (±0.00%)   | 12.615s (±0.00%)   | -0.13%    | 35.548mb        | 35.548mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 9.161s (±0.00%)    | 9.183s (±0.00%)    | -0.24%    | 36.050mb        | 36.050mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

This comment gets update everytime a new commit comes in!