Added bookmarks

• Added:
- bookmarks for GabPRO members only
- migration for creation of StatusBookmarks
- all necessary routes, controllers
- redux for adding, removing, fetching and displaying bookmarks
- bookmark icon
- doorkeeper scopes
- backend and frontend support

Bookmarks behave like likes/favorites, except they aren't shared with other users and do not have an associated counter.

https://github.com/tootsuite/mastodon/commit/dfea7368c934f600bd0b6b93b4a6c008a4e265b0

app/javascript/gabsocial/features/ui/util/async_components.js

@@ -3,6 +3,7 @@ export function AccountTimeline() { return import(/* webpackChunkName: "features
 export function AccountGallery() { return import(/* webpackChunkName: "features/account_gallery" */'../../account_gallery') }
 export function BlockAccountModal() { return import(/* webpackChunkName: "components/block_account_modal" */'../../../components/modal/block_account_modal') }
 export function BlockedAccounts() { return import(/* webpackChunkName: "features/blocked_accounts" */'../../blocked_accounts') }
+export function BookmarkedStatuses() { return import(/* webpackChunkName: "features/bookmarked_statuses" */'../../bookmarked_statuses') }
 export function BoostModal() { return import(/* webpackChunkName: "components/boost_modal" */'../../../components/modal/boost_modal') }
 export function CommentSortingOptionsPopover() { return import(/* webpackChunkName: "components/comment_sorting_options_popover" */'../../../components/popover/comment_sorting_options_popover') }
 export function CommunityTimeline() { return import(/* webpackChunkName: "features/community_timeline" */'../../community_timeline') }