Add mssql integration tests and relocate existing unit tests

[shahar1]

closes: #38577

This PR:

• Relocates existing unit tests for mssql from the integration directory back to the unit tests (see Restore providers' unit tests marked as integration tests #39768)
• Creates a Docker Compose integration yaml file for mssql.
• Adds an integration test for mssql hook.
• Adds integration tests for:
  • bigquery_to_mssql.py
  • mssql_to_gcs.py
  • mssql_to_hive.py

cc: @potiuk, @Taragolis, @eladkal

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[potiuk]

Nice. - few nits and solving failing tests (I guess some rebase needed?)

[potiuk]

One more thing: you also need to add Mssql as individual integration to test in .github/workflows/integration-tests.yml. This way the integration tests will be run on public runners (only in self-hosted runners all integrations are run together).

[potiuk]

Nice!

[potiuk]

@eladkal @shahar1 I also added #39866 as follow-up -> I realized that the last step was not obvious (having to add integration test step to integration-tests.yml was quite a bit duplication - also recently the "self-hosted" "all-testable" integrations when all of the integrations are started together have been somewhat flaky (as opposed to individual integrations) - so the #39866 will simplify it: removes the duplication and always runs the integration tests individually on public runners for both mssql and postgres.