Replace dependant trs tables by json field in trs table

[lsilvs]

Expected behavior

I expect to any custom transaction to be able to store its asset data without creating a migrations.

As a result we can get rid of full_blocks_list view (which is expensive) and its dependant tables:

delegates
votes
signatures
multisignatures
dapps
intransfer
outtransfer
transfer

Actual behavior

Currently, if I want to introduce a new transaction type with assets I have to write a migration to add new table.
By introducing a json field in trs table all related asset can be saved there and different transactions can have different asset structures.

Which version(s) does this affect? (Environment, OS, etc...)

1.5

[MaciejBaj]

That's the improvement we've already planned to do for a long time and which was initially intended to do as part of Lisk Core v1.6.

We will implement this refactor sooner - in Lisk Core v1.5, as the removal of full_blocks_list and doing SQL queries on trs.asset column as JSON directly, will significantly improve the API performance of transactions related endpoints which dropped significantly in Lisk Core 1.5 - #2817.