* This PR changes the user activity bookmarks stream to show a new list of bookmarks based on the Bookmark record.
* If a bookmark has a name or reminder it will be shown as metadata above the topic title in the list
* The categories, tags, topic status, and assigned show for each bookmarked post based on the post topic
* Bookmarks can be deleted from the [...] menu in the list
* As well as this, the list of bookmarks from the quick access panel is now drawn from the Bookmarks table for a user:
* All of this new functionality is gated behind the enable_bookmarks_with_reminders site setting
The /bookmarks/ route now redirects directly to /user/:username/activity/bookmarks-with-reminders
* The structure of the Ember for the list of bookmarks is not ideal, this is an MVP PR so we can start testing this functionality internally. There is a little repeated code from topic.js.es6. There is an ongoing effort to start standardizing these lists that will be addressed in future PRs.
* This PR also fixes issues with feature detection for at_desktop bookmark reminders
* 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`
