Enforce keeping coverage minimums up-to-date in Code Coverage CI workflow

[thnkslprpt]

Is your feature request related to a problem? Please describe.
Code coverage minimums seem to go out-of-date quite often.
When these values aren't updated, the code coverage workflow will pass and it's likely that no alert will occur if a new PR reduces test coverage.

Describe the solution you'd like
Fail the code coverage workflow if a PR improves coverage but hasn't updated (lowered) the missed branches/lines variables in the workflow file.

Describe alternatives you've considered
Leave as-is and check periodically that these minimum coverage variables are still up-to-date.

Requester Info
Avi Weiss   @thnkslprpt