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/mkdirp-classic/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "mkdirp-classic",
+  "version": "0.5.3",
+  "description": "Mirror of mkdirp 0.5.2",
+  "main": "index.js",
+  "dependencies": {},
+  "devDependencies": {},
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/mafintosh/mkdirp-classic.git"
+  },
+  "author": "Mathias Buus (@mafintosh)",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/mafintosh/mkdirp-classic/issues"
+  },
+  "homepage": "https://github.com/mafintosh/mkdirp-classic"
+}