Request: confirmation when clearing all pinned threads

[bakugo]

Twice now I have deleted hundreds of pinned threads by accidentally pressing the clear all button instead of the watch toggle button.

I'm aware that an "undo" button pops up for a few seconds, but when clearing many pins, the app will freeze for a significant amount of time and a "Clover is not responding" overlay will often pop up. If you're not ready to press "undo" as soon as it unfreezes, the pins are gone and there's no way to get them back.

[floens]

I think it's better to not let Clover hang on deleting so many pins.