Make the shared table used in the cFE functional tests configurable

[dmknutsen]

Is your feature request related to a problem? Please describe.
Projects typically will remove sample_app from their build. This creates an issue because the cFE functional tests are dependent on it such that tests will fail after removal. Need a mechanism to easily swap out the sample_app table used in the functional tests such that projects can still run the tests as part of their CI/CD once sample_app is removed.

Describe the solution you'd like
Make the name of the table used in the cFE functional tests configurable such that projects can easily swap out the sample_app table with a table in their project specific build.

Requester Info
Dan Knutsen
NASA Goddard