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/abstract-leveldown/test/util.js

@@ -0,0 +1,10 @@
+var nfre = /NotFound/i
+
+exports.verifyNotFoundError = function verifyNotFoundError (err) {
+  return nfre.test(err.message) || nfre.test(err.name)
+}
+
+exports.isTypedArray = function isTypedArray (value) {
+  return (typeof ArrayBuffer !== 'undefined' && value instanceof ArrayBuffer) ||
+    (typeof Uint8Array !== 'undefined' && value instanceof Uint8Array)
+}