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/reusify/benchmarks/fib.js

@@ -0,0 +1,13 @@
+'use strict'
+
+function fib (num) {
+  var fib = []
+
+  fib[0] = 0
+  fib[1] = 1
+  for (var i = 2; i <= num; i++) {
+    fib[i] = fib[i - 2] + fib[i - 1]
+  }
+}
+
+module.exports = fib