sub-command support for ACL CAT and COMMAND LIST. redisCommand always stores fullname (#10127)

Summary of changes:
1. Rename `redisCommand->name` to `redisCommand->declared_name`, it is a
  const char * for native commands and SDS for module commands.
2. Store the [sub]command fullname in `redisCommand->fullname` (sds).
3. List subcommands in `ACL CAT`
4. List subcommands in `COMMAND LIST`
5. `moduleUnregisterCommands` now will also free the module subcommands.
6. RM_GetCurrentCommandName returns full command name

Other changes:
1. Add `addReplyErrorArity` and `addReplyErrorExpireTime`
2. Remove `getFullCommandName` function that now is useless.
3. Some cleanups about `fullname` since now it is SDS.
4. Delete `populateSingleCommand` function from server.h that is useless.
5. Added tests to cover this change.
6. Add some module unload tests and fix the leaks
7. Make error messages uniform, make sure they always contain the full command
  name and that it's quoted.
7. Fixes some typos

see the history in #9504, fixes #10124

Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: guybe7 <guy.benoish@redislabs.com>