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/preact/compat/src/PureComponent.js

@@ -0,0 +1,16 @@
+import { Component } from 'preact';
+import { shallowDiffers } from './util';
+
+/**
+ * Component class with a predefined `shouldComponentUpdate` implementation
+ */
+export function PureComponent(p, c) {
+	this.props = p;
+	this.context = c;
+}
+PureComponent.prototype = new Component();
+// Some third-party libraries check if this property is present
+PureComponent.prototype.isPureReactComponent = true;
+PureComponent.prototype.shouldComponentUpdate = function (props, state) {
+	return shallowDiffers(this.props, props) || shallowDiffers(this.state, state);
+};