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/buffer-from/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "buffer-from",
+  "version": "1.1.2",
+  "license": "MIT",
+  "repository": "LinusU/buffer-from",
+  "files": [
+    "index.js"
+  ],
+  "scripts": {
+    "test": "standard && node test"
+  },
+  "devDependencies": {
+    "standard": "^12.0.1"
+  },
+  "keywords": [
+    "buffer",
+    "buffer from"
+  ]
+}