Fix #288, Remove unnecessary CF_UnionArgs_Payload_t union

[thnkslprpt]

Checklist

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License Agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution

• Fixes CF_UnionArgs_Payload_t elements dword and hword not used, union not necessary #288
  CF_UnionArgs_Payload_t has been removed, given that only a single member of the 3 is used in CF. That member variable - byte - has been moved into the CF_UnionArgsCmd_t struct, which was the only place where CF_UnionArgs_Payload_t was used.

• Re-introduced from Fix #288, Remove unnecessary CF_UnionArgs_Payload_t union #341. Move PR #341 into Equuleus-rc2 #393, Fix #393, revert merge of PR #341. #395 reverted this PR due to integration issues. Resubmitting here for consideration in next release.

Testing performed
GitHub CI actions (incl. Build + Run, Unit Tests etc.) all passing successfully.

Expected behavior changes
No impact on logic.
Code is simplified and clearer.

Contributor Info
Avi Weiss @thnkslprpt

[jphickey]

We need to also do this but I'd like to approach it a bit differently. Although only the "byte" field is used now, it is still used for a few different things in different commands. Now that each command has its own definition, this should be made type-correct.

[thnkslprpt]

We need to also do this but I'd like to approach it a bit differently. Although only the "byte" field is used now, it is still used for a few different things in different commands. Now that each command has its own definition, this should be made type-correct.

@jphickey So you want to create command-specific struct members for each command?
What exactly do you mean in terms of the solution to make it type-correct?
Cheers