fix: allow clearing database inside a transaction

[varanauskas]

Possible fix for: #8527

Description of change

This is one of the possible fixes for the issue #8527

It allows to run clearDatabase inside a transaction by making clearDatabase to check if another transaction is already running and not creating a new transaction in that case

It currently is only developed for/tested with Postgres, if this is the right direction same fix could be applied for other query runners

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 #0000
• 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

[varanauskas]

This is re-opening of my previous pull request #8529

I have merged the rebased with master and adapted the necessary changes to all drivers that use transactions when clearing database

[pleerock]

Thank you