[database] Fix, test connection error message for module not found

[dpgaspar]

CATEGORY

• Bug Fix
• Enhancement (new features, refinement)
• Refactor
• Add tests
• Build / Development Environment
• Documentation

SUMMARY

On MSSQL and probably using other drivers, if pymssql is missing testconn API response is "Unexpected error occurred, please check your logs for details" and should be "Could not load database driver: ..."

TEST PLAN

• Create a database connection with: mssql+pymssql://someserver:1433/test
• Check that the error reported is "ERROR: Could not load database driver: mssql+pymssql"

ADDITIONAL INFORMATION

• Has associated issue:
• Changes UI
• Requires DB Migration.
• Confirm DB Migration upgrade and downgrade tested.
• Introduces new feature or API
• Removes existing feature or API

REVIEWERS

[willbarrett]

Would it be possible to add a test for this case?

[villebro]

Hmm, I wasn't able to reproduce with the test string something+dummy://someserver:9999/test. Were you testing a specific driver when this came up?

[dpgaspar]

@villebro

Caught this while testing MSSQL, so used:
mssql+pymssql://sa:XXXXXXXXXX@localhost:1433/msdb

You can reproduce it by removing the pymssql from the virtualenv

Yet, you're right, my assumption is not totally correct, updated the PR description