Add cFE Memory Manager API functional tests

[skliper]

Is your feature request related to a problem? Please describe.
Need open source functional tests for certifiability

Describe the solution you'd like
Add cFE Memory Manager API functional tests
– CFE_ES_PoolCreate - Initializes a memory pool created by an application while using a semaphore during
processing.
– CFE_ES_PoolCreateEx - Initializes a memory pool created by an application with application specified block
sizes.
– CFE_ES_PoolCreateNoSem - Initializes a memory pool created by an application without using a
semaphore during processing.
– CFE_ES_GetPoolBuf - Gets a buffer from the memory pool created by CFE_ES_PoolCreate or CFE_ES -
_PoolCreateNoSem.
– CFE_ES_PutPoolBuf - Releases a buffer from the memory pool that was previously allocated via CFE_E -
S_GetPoolBuf.
– CFE_ES_GetMemPoolStats - Extracts the statistics maintained by the memory pool software.
– CFE_ES_GetPoolBufInfo - Gets info on a buffer previously allocated via CFE_ES_GetPoolBuf.

Describe alternatives you've considered
N/A

Additional context
N/A

Requester Info
Jacob Hageman - NASA/GSFC

[jphickey]

Question - should we consider finally implementing #56 as part of this? Consolidating this code would simplify functional testing (one set or routines to implement, instead of two) as well as helping out with #651. I had started implementing this a long time ago (CFE 6.5 timeframe) but never had the opportunity to finish/merge it, but it might still exist in one of my branches somewhere.

[skliper]

Yes. I'd think it would make sense to group all the mempool issues and resolve them. A couple of them are required in the next release either way, so might as well refactor while we are at it to make everything simpler.