FRE-600: Fix code review blockers

- Consolidated duplicate UndoManagers to single instance
- Fixed connection promise to only resolve on 'connected' status
- Fixed WebSocketProvider import (WebsocketProvider)
- Added proper doc.destroy() cleanup
- Renamed isPresenceInitialized property to avoid conflict

Co-Authored-By: Paperclip <noreply@paperclip.ing>

node_modules/core-js/proposals/set-methods.js

@@ -0,0 +1,17 @@
+'use strict';
+// https://github.com/tc39/proposal-set-methods
+require('../modules/esnext.set.difference.v2');
+require('../modules/esnext.set.intersection.v2');
+require('../modules/esnext.set.is-disjoint-from.v2');
+require('../modules/esnext.set.is-subset-of.v2');
+require('../modules/esnext.set.is-superset-of.v2');
+require('../modules/esnext.set.union.v2');
+require('../modules/esnext.set.symmetric-difference.v2');
+// TODO: Obsolete versions, remove from `core-js@4`
+require('../modules/esnext.set.difference');
+require('../modules/esnext.set.intersection');
+require('../modules/esnext.set.is-disjoint-from');
+require('../modules/esnext.set.is-subset-of');
+require('../modules/esnext.set.is-superset-of');
+require('../modules/esnext.set.union');
+require('../modules/esnext.set.symmetric-difference');