FEATURE: Send notifications for time-based and At Desktop bookmark reminders (#9071)

* This PR implements the scheduling and notification system for bookmark reminders. Every 5 minutes a schedule runs to check any reminders that need to be sent before now, limited to **300** reminders at a time. Any leftover reminders will be sent in the next run. This is to avoid having to deal with fickle sidekiq and reminders in the far-flung future, which would necessitate having a background job anyway to clean up any missing `enqueue_at` reminders.

* If a reminder is sent its `reminder_at` time is cleared and the `reminder_last_sent_at` time is filled in. Notifications are only user-level notifications for now.

* All JavaScript and frontend code related to displaying the bookmark reminder notification is contained here. The reminder functionality is now re-enabled in the bookmark modal as well.

* This PR also implements the "Remind me next time I am at my desktop" bookmark reminder functionality. When the user is on a mobile device they are able to select this option. When they choose this option we set a key in Redis saying they have a pending at desktop reminder. The next time they change devices we check if the new device is desktop, and if it is we send reminders using a DistributedMutex. There is also a job to ensure consistency of these reminders in Redis (in case Redis drops the ball) and the at desktop reminders expire after 20 days.

* Also in this PR is a fix to delete all Bookmarks for a user via `UserDestroyer`

app/services/user_destroyer.rb

@@ -28,6 +28,7 @@ class UserDestroyer
     optional_transaction(open_transaction: opts[:transaction]) do
 
       UserSecurityKey.where(user_id: user.id).delete_all
+      Bookmark.where(user_id: user.id).delete_all
       Draft.where(user_id: user.id).delete_all
       Reviewable.where(created_by_id: user.id).delete_all