Updating tests

[hamshavathimunibyraiah]

Updating tests:

1. Authenticating storage accounts using MI
2. SAS urls are no longer needed to access containers using DefaultAzureCredential instead
3. Updated test-resource.json inline with what we have for other langs
4. Updating resource output variable names accordingly.
5. Updated text translation test cases: updated resource output names
6. Added test cases for the overridden models and operations (startTranslation using start_translation_details)

[azure-sdk]

API change check

API changes are not detected in this pull request.

[hamshavathimunibyraiah]

/azp run python - translation - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[hamshavathimunibyraiah]

/azp run python - translation - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).