Users can now pin bookmarks from their bookmark list. This will anchor the bookmark to the top of the list, and show a pin icon next to it. This also applies in the nav bookmarks panel. If there are multiple pinned bookmarks they sort by last updated order.
* Remove unneeded bookmark name index.
* Change bookmark search query to use post_search_data. This allows searching on topic title and post content
* Tweak the style/layout of the bookmark list so the search looks better and the whole page fits better on mobile.
