Restore connection context if exception happens during rollback or commit

[henadzit]

Description

Fixes the issue where if an exception happens during a rollback or commit, the connection context is not properly restored leading to having TransactionWrapper where regular connections are supposed to be. This would also cause connections not properly recycled in the case of database downtime.

Motivation and Context

This should fix #1793 and fix #1604

How Has This Been Tested?

• Tests
• Ran a web app locally.
• Ran the test case from Tortoise never recovers from Postgres downtime if transactions are used #1793

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added the changelog accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[coveralls]

Pull Request Test Coverage Report for Build 12118174684

Details

• 21 of 21 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.002%) to 90.392%

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Totals
Change from base Build 12116630665:	0.002%
Covered Lines:	6314
Relevant Lines:	6879

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💛 - Coveralls