CFE_ES_POOL_BOUNDS_ERROR defined but not used

[jphickey]

Is your feature request related to a problem? Please describe.
This error code was added at one point as a return value from CFE_ES_PoolCreateEx when there was an issue that caused the pool to go beyond the allocated size. However now the code validates the size before even starting to create the pool, and returns CFE_ES_BAD_ARGUMENT if it is too small.

So now the CFE_ES_POOL_BOUNDS_ERROR has become stale, nothing uses this error anymore.

Describe the solution you'd like
Remove value from cfe_error.h and remove any remaining references to it.

Additional context
Noted as part of scrub in #1724

Requester Info
Joseph Hickey, Vantage Systems, Inc.