module and vault fixes (#29663)

* module and vault fixes

- fix module_path cli option and usage, which fixes #29653
- move --output to be in subset of vault cli, no need for all vault enabled cli to use it
- added debug to loader to see directories added

lib/ansible/plugins/loader.py

@@ -229,6 +229,7 @@ class PluginLoader:
                 # append the directory and invalidate the path cache
                 self._extra_dirs.append(directory)
                 self._paths = None
+                display.debug('Added %s to loader search path' % (directory))
 
     def find_plugin(self, name, mod_type='', ignore_deprecated=False, check_aliases=False):
         ''' Find a plugin named name '''