* Give lightbox a background load animation
* Extends IMediaEventContent by thumbnail info
* Give image view panel a loading animation
* Initial implementation of loading animation
* Take panel height into account
* Update animation speed
* Add some null guards
* Fix animation issues
* Move animations into _animations
* Where does that magic number come from?
* Remove awaiting setState()
* Use CSS var in JS
* Handle prefers-reduced-motion
* More prefers-reduced-motion friendliness
Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>