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/collection-of.js

@@ -0,0 +1,15 @@
+'use strict';
+var anObject = require('../internals/an-object');
+
+// https://tc39.github.io/proposal-setmap-offrom/
+module.exports = function (C, adder, ENTRY) {
+  return function of() {
+    var result = new C();
+    var length = arguments.length;
+    for (var index = 0; index < length; index++) {
+      var entry = arguments[index];
+      if (ENTRY) adder(result, anObject(entry)[0], entry[1]);
+      else adder(result, entry);
+    } return result;
+  };
+};