Strict aliasing build errors in unit test code

[jphickey]

Describe the bug
When using strict aliasing in combination with tests (i.e. ENABLE_UNIT_TESTS=true), additional aliasing warnings are produced by GCC 10.3.

To Reproduce
Build CFE with tests enabled along with strict aliasing compiler settings (-O3 -fstrict-aliasing -Wstrict-aliasing=2), build will fail with errors such as:

<top>/cfe/modules/core_api/ut-stubs/src/cfe_es_handlers.c: In function ‘UT_DefaultHandler_CFE_ES_GetAppID’:
<top>/cfe/modules/core_api/ut-stubs/src/cfe_es_handlers.c:136:60: error: dereferencing type-punned pointer might break strict-aliasing rules [-Werror=strict-aliasing]
  136 |         UT_GetDataBuffer(UT_KEY(CFE_ES_GetAppID), (void **)&IdBuff, &BuffSize, &Position);
      |                                                            ^~~~~~~
<top>/cfe/modules/core_api/ut-stubs/src/cfe_es_handlers.c: In function ‘UT_DefaultHandler_CFE_ES_GetTaskID’:
<top>/cfe/modules/core_api/ut-stubs/src/cfe_es_handlers.c:170:61: error: dereferencing type-punned pointer might break strict-aliasing rules [-Werror=strict-aliasing]
  170 |         UT_GetDataBuffer(UT_KEY(CFE_ES_GetTaskID), (void **)&IdBuff, &BuffSize, &Position);
      |                                                             ^~~~~~~

Expected behavior
Should build cleanly

System observed on:
Ubuntu 21.04 (w/gcc 10.3)

Additional context
Most of these are related to (void**) casts, which is easily resolved by making another local void* variable to temporarily hold the pointer.

Reporter Info
Joseph Hickey, Vantage Systems, Inc.