Fix memory leak in moduleFreeCommand (#11147)

Currently, we call zfree(cmd->args), but the argument array
needs to be freed recursively (there might be sub-args).
Also fixed memory leaks on cmd->tips and cmd->history.

Fixes #11145

tests/unit/moduleapi/cmdintrospection.tcl

@@ -40,4 +40,8 @@ start_server {tags {"modules"}} {
 
         assert_equal $redis_reply $module_reply
     }
+
+    test "Unload the module - cmdintrospection" {
+        assert_equal {OK} [r module unload cmdintrospection]
+    }
 }