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/which-module/index.js

@@ -0,0 +1,9 @@
+'use strict'
+
+module.exports = function whichModule (exported) {
+  for (var i = 0, files = Object.keys(require.cache), mod; i < files.length; i++) {
+    mod = require.cache[files[i]]
+    if (mod.exports === exported) return mod
+  }
+  return null
+}