Reevaluate window rules when the (xdg) shell surface's appId changes

Summary:
Especially when a window is first mapped it might be that the appId is
not yet set. So window rule matching doesn't happen. This change
evaluates the window rules again after the appId changes, so rules for
the appId match.

Test Plan: added test case

Reviewers: KWin, Plasma

Subscribers: kwin

Tags: KWin

Differential Revision: https://phabricator.kde.org/D11268