CFE_SB_GetBufferFromPool discarding CFE_ES_GetPoolBuf error status

[skliper]

Is your feature request related to a problem? Please describe.
Many error cases within CFE_ES_GetPoolBuf just set the status code and return (no reporting). Then CFE_SB_GetBufferFromPool just discards it. Arguably not compliant with mission critical code requirements.

cFE/modules/sb/fsw/src/cfe_sb_buf.c

Lines 105 to 110 in e35c3da

	/* Allocate a new buffer descriptor from the SB memory pool.*/
	stat1 = CFE_ES_GetPoolBuf(&addr, CFE_SB_Global.Mem.PoolHdl, AllocSize);
	if (stat1 < 0)
	{
	return NULL;
	}

Describe the solution you'd like
Definitely not the only case where returns get discarded or ignored (see #549) but this one is a significant shortcoming. Affects CFE_SB_TransmitMsg and CFE_SB_AllocateMessageBuffer.

Describe alternatives you've considered
Although apps need to check for a null return from CFE_SB_AllocateMessageBuffer either way, the error code is lost by that point. Another good use case for #1469, since you wouldn't want to flood events or sys log but the failure type and count is very important for monitoring system health.

Additional context
None

Requester Info
Jacob Hageman - NASA/GSFC