appmenus: register event handlers on QubesVM, not BaseVM

It is critical to call rename-related events in the right order related
to those in QubesVM, because handler at QubesVM renames VM directory.

After "qubes/events: fix event handlers ordering" in qubes-core-admin it
is (again) possible to deterministically order event handler from
extension in relation to those from the class itself. But since ordering
on object class have higher priority (first from base class), those
handlers needs to be attached to the same class.

qubesappmenus/__init__.py

@@ -300,13 +300,13 @@ class AppmenusExtension(qubes.ext.Extension):
             return
         shutil.rmtree(self.icons_dir(vm))
 
-    @qubes.ext.handler('property-pre-set:name')
+    @qubes.ext.handler('property-pre-set:name', vm=qubes.vm.qubesvm.QubesVM)
     def pre_rename(self, vm, event, prop, *args):
         if not os.path.exists(vm.dir_path):
             return
         self.appmenus_remove(vm)
 
-    @qubes.ext.handler('property-set:name')
+    @qubes.ext.handler('property-set:name', vm=qubes.vm.qubesvm.QubesVM)
     def post_rename(self, vm, event, prop, *args):
         if not os.path.exists(vm.dir_path):
             return