Introduce PropertyAnimator

[lenemter]

Converts some window manager effect to use PropertyAnimator, which can handle disabled animations correctly by itself.

[leolost2605]

I'm wondering whether it would be better to just have two utils methods something like this

Utils.prepare_animation (actor, time, mode);
// set actor properties 
actor.translation_x = 5;
Utils.run_animation (actor, () => { 
    // do some stuff after the animation finished
});

The utils methods would then just save and restore easing state depending on whether animations are enabled and the run_animation would then immediately call the callback or connect to the finished signal of an animation and then call the callback.
This would be less code and you can't accidentally write a property name wrong or have a type wrong.
This was just an idea and I'm open to other arguments though so lmk what you think 🤷

[lenemter]

@leolost2605 I don't like this approach. The main downside of what you suggested is that there's no way to get the animated properties, so you have to use Clutter.Actor.transitions_completed and it can lead to some issues -- if you animate the actor two times, the on_stopped handlers might get fired at incorrect timing.

I don't really like passing properties around as strings, but I don't think there's a way around that unfortunately =( For now I added a warning when property name is incorrect. I'll see if I can find more robust way to pass properties (GLib.ParamSpec maybe?)