Fix #1417, Fix #1418, Fix workflow bug and enforce updating of coverage minimums

[thnkslprpt]

Checklist

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License Agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution

• Fixes Subtle bug in Code Coverage CI workflow #1418
  • Removes this bug by adding a condition to the coverage check workflows to only run in debug builds (by checking for env.run_lcov == 'TRUE', which is what triggers the 'Check Coverage' step to run)
  • Also removed the condition to only run the coverage workflows in the ubuntu-20.04 debug build - now it will run fully in both the 20.04 and 22.04 debug builds. Happy to change this back if there is some specific reason to limit these checks to only 20.04.
• Fixes Enforce keeping coverage minimums up-to-date in Code Coverage CI workflow #1417
  • Adds additional steps in the code coverage workflow to check that the missed functions/lines/branches variables are kept up to date.

Testing performed
Tested all variations of coverage thresholds (above, below, split between functions/lines/branches etc.) to confirm expected behavior.

New checks:

Expected behavior changes
Any PR that improves coverage will cause the workflow to fail now unless the allowed_ncov_lines, allowed_ncov_branches and/or allowed_ncov_functions variables are updated as part of the same PR.

System(s) tested on
Debian GNU/Linux 11 (bullseye)
Current main branch of cFS bundle.

Contributor Info
Avi Weiss   @thnkslprpt

[thnkslprpt]

FYI @dzbaker I rebased this to main and updated it to make the plural/singular wording automatic.

[dzbaker]

FYI @dzbaker I rebased this to main and updated it to make the plural/singular wording automatic.

Thanks!