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/pngjs/lib/png-sync.js

@@ -0,0 +1,12 @@
+"use strict";
+
+let parse = require("./parser-sync");
+let pack = require("./packer-sync");
+
+exports.read = function (buffer, options) {
+  return parse(buffer, options || {});
+};
+
+exports.write = function (png, options) {
+  return pack(png, options);
+};