Summary:
EffectWindow proxies its properties from the client/deleted's
properties.

QObject::property(char*) is a slow string search. It's a loop
of string comparisons not a hash lookup!

QML's use of properties is different, there's a property cache.

It's fetched multiple times for every window in every paint of some
effects (such as blur). Hotspot shows this as a significant amount of
the render pass (X11) with nothing in kwin animating.

This patch replaces the macro that does
parent()->property("propertyName")
with a macro calling the relevant function directly without metaobjects.

This also improves type safety for future changes.

Test Plan:
Existing unit tests
Ran it for a bit

Reviewers: #kwin, graesslin

Subscribers: graesslin, zzag, broulik, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D16602