Support for CSS animations matches our browser support matrix on Mw.org
Let's drop the method and use of the animations class it adds.
- Usages of .animation class inside Minerva and MobileFrontend are removed
- Tests and method are removed.
- When logged out click watchstar. Ensure the opening and closing of the drawer is animated
- Open the menu and close it - confirming it is animated.
- Log in and click the notification button in the top right on a desktop device. Confirm it is animated.