Add explain verbose with limit push down

[jimexist]

Which issue does this PR close?

fix explain verbose with limit push down

re #733

Rationale for this change

What changes are included in this PR?

before fix:

> create external table test stored as PARQUET location '/Users/jiayu_liu/Desktop/aggregate_test_100.parquet';
0 rows in set. Query took 0.001 seconds.
> explain verbose select c3, c9 from test limit 3;
+-----------------------------------------+----------------------------------------------------------------------------------------------------------------+
| plan_type                               | plan                                                                                                           |
+-----------------------------------------+----------------------------------------------------------------------------------------------------------------+
| logical_plan                            | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=None                                                                            |
| logical_plan after projection_push_down | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8])                                                                    |
| logical_plan after simplify_expressions | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8])                                                                    |
| logical_plan after projection_push_down | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8])                                                                    |
| logical_plan after simplify_expressions | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8])                                                                    |
| physical_plan                           | GlobalLimitExec: limit=3                                                                                       |
|                                         |   ProjectionExec: expr=[c3@0 as c3, c9@1 as c9]                                                                |
|                                         |     ParquetExec: batch_size=8192, limit=None, partitions=[/Users/jiayu_liu/Desktop/aggregate_test_100.parquet] |
+-----------------------------------------+----------------------------------------------------------------------------------------------------------------+

after the fix

> create external table test stored as PARQUET location '/Users/jiayu_liu/Desktop/aggregate_test_100.parquet';
0 rows in set. Query took 0.001 seconds.
> explain verbose select c3, c9 from test limit 3;
+-----------------------------------------+----------------------------------------------------------------------------------------------------------------+
| plan_type                               | plan                                                                                                           |
+-----------------------------------------+----------------------------------------------------------------------------------------------------------------+
| logical_plan                            | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=None                                                                            |
| logical_plan after projection_push_down | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8])                                                                    |
| logical_plan after simplify_expressions | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8])                                                                    |
| logical_plan after limit_push_down      | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8]), limit=3                                                           |
| logical_plan after projection_push_down | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8]), limit=3                                                           |
| logical_plan after simplify_expressions | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8]), limit=3                                                           |
| logical_plan after limit_push_down      | Limit: 3                                                                                                       |
|                                         |   Projection: #test.c3, #test.c9                                                                               |
|                                         |     TableScan: test projection=Some([2, 8]), limit=3                                                           |
| physical_plan                           | GlobalLimitExec: limit=3                                                                                       |
|                                         |   ProjectionExec: expr=[c3@0 as c3, c9@1 as c9]                                                                |
|                                         |     ParquetExec: batch_size=3, limit=Some(3), partitions=[/Users/jiayu_liu/Desktop/aggregate_test_100.parquet] |
+-----------------------------------------+----------------------------------------------------------------------------------------------------------------+

Are there any user-facing changes?

[alamb]

Thank you @jimexist -- this definitely is an improvement (and relates to #733)

One thing that bothers me about #733 is that each optimizer pass needs to handle explain plans specially, but I think that means we end up missing some of them (and also not catching user defined optimizer passes)

I am thinking it might be better to (eventually) handle explain plan capturing in the planners. I'll try and work on that after #744

[Dandandan]

Nice fix @jimexist