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/internals/math-sign.js

@@ -0,0 +1,9 @@
+'use strict';
+// `Math.sign` method implementation
+// https://tc39.es/ecma262/#sec-math.sign
+// eslint-disable-next-line es/no-math-sign -- safe
+module.exports = Math.sign || function sign(x) {
+  var n = +x;
+  // eslint-disable-next-line no-self-compare -- NaN check
+  return n === 0 || n !== n ? n : n < 0 ? -1 : 1;
+};