feat: add nested transaction

[mortezaPRK]

Description of change

Add nested transaction support.

Implemented following drivers:

• mysql
• postgres
• mariadb
• sqlite
• react-native
• nativescript
• sqljs
• oracle
• better-sqlite3
• capacitor

Following drivers also support nested transaction. but I'm not familiar with them:

• cockroachdb
• mssql
• aurora-data-api
• aurora-data-api-pg
• expo

May be someone else can implement it in another PR

Fixes: #1505

Pull-Request Checklist

• Code is up-to-date with the master branch
• npm run lint passes with this change
• npm run test passes with this change
• This pull request links relevant issues as Fixes #1505
• There are new or updated unit tests validating the change
• Documentation has been updated to reflect this change
• The new commits follow conventions explained in CONTRIBUTING.md

This is WIP. if implementation is acceptable, I'll add other drivers and tests

[pleerock]

Thank you for your contribution, looks really good. Considering simplicity of the suggested solution, I just wanted to ask you if you have a time to investigate other drivers as well, because:

cockroachdb - should be same as postgres if they support it
aurora-data-api - should be same as mysql
aurora-data-api-pg - should be same as postgres
expo - should be same as sqlite
mssql - would be really nice to have since others are implemented

[mortezaPRK]

sure. I'll give it a try tomorrow

[mortezaPRK]

@pleerock

I added other drivers except for mssql. I wasn't able to implement it :(

[AlexMesser]

thank you for contribution!

[xfishernet]

I try this example and it still doesn't work for me :-(

#1505

[Gideon-Felt]

Is mssql still not capable of using this feature?