Port plasma-integration to explicit wayland AppMenu protocol
Summary:
Also fixed to handle the case of surfaces not having the lifespan of the
window, which the old code didn't handle.
I don't think it's worth trying to handle the case of different versions
of kwin and plasma-integration.
Test Plan: Made relevant kwin change and it gets communicated fine
Reviewers: Plasma
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D9248