Yari Polla authored Jun 24, 2022 and Devin Lin committed Jun 25, 2022

Hi, this MR adds "clear all" and "do not disturb" buttons to `NotificationsWidget`.

Few other corrections have been made:
 - Transitions should now work correctly, plus they can be disabled via `MobileShell.MobileShellSettings.animationsEnabled`;
 - Loaders are now asynchronous;
 - List items have now their own margins, in order to not clip their shadows.\

It only remains to implement a context menu to set do not disturb mode for a given period of time. I think it's a secondary feature on which we can work later, but in case tell me what to do.

Unfortunately I can't test the lockscreen on a phone at the moment, and I cannot take a performance test as well. It would be great if someone tested all these things, otherwise I'll provide as soon as possible.

Closes: #134