Fix/discovery database permissions error

[dmosorast]

Description of change

https://stitchdata.atlassian.net/browse/SUP-1512

The behavior of tap-mssql, it seems, differs from the other database taps, in that, there are cases of permissions where a user doesn't have access to all databases, in which case the tap fails.

This PR handles a very specific permissions error that can occur during discovery to align this behavior with other database taps.

The solution to fall back to a try/catch pattern came from the apparent lack of ability to query a user's permissions on a database without first connecting to the database (at which point an exception would be raised if they have no access).

QA steps

• manual qa steps passing (list below)
  • Ran through a bunch of queries on local test DB and wrote local integration test for this case

Risks

Low, it's just error handling.

Rollback steps

• revert this branch, bump patch, release

[asaf-erlich]

Looks good to me but please ask someone who more clojure and / or general tap review experience.