Signal which menu has updated in libdbusmenu-qt
Summary:
Then update appet, SNI, and appmenu appropriately which are only care
about the root menu.
This fixes some premature showing and re-evaluation.
Test Plan:
Ran statusnotifiertest and checked submenu worked
Ran applet and checked everything was still fine
Restarted kded and checked window decoration menu
Reviewers: Plasma
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D4161