Enforce cFE code coverage minimum statistics

[skliper]

Is your feature request related to a problem? Please describe.
Code coverage not enforced, so it's easy to miss where code modifications should trigger coverage test updates

Describe the solution you'd like
Enforce (like OSAL) maximum uncovered lines/branches in CI. Would benefit from an additional makefile rule or similar to separate and report out just cFE coverage.

Describe alternatives you've considered
None

Additional context
Should enforce as soon as the full coverage scrub is complete. As we address missing coverage issues in the future we can adjust the limits.

Requester Info
Jacob Hageman - NASA/GSFC