[scripting] Re-evaluate exclusions after switching between virtual desktops or activities

Summary:
OtherDesktopsExclusion and OtherActivitiesExclusion flags must be
re-evaluated after user has switched between virtual desktops or
activities; otherwise ClientLevel may contain clients that are not
necessarily on the current virtual desktop or activity.

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: kwin

Tags: #kwin

Maniphest Tasks: T12877

Differential Revision: https://phabricator.kde.org/D28827