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/core-js/stable/set/difference.js

@@ -0,0 +1,4 @@
+'use strict';
+var parent = require('../../es/set/difference');
+
+module.exports = parent;

node_modules/core-js/stable/set/index.js

@@ -0,0 +1,5 @@
+'use strict';
+var parent = require('../../es/set');
+require('../../modules/web.dom-collections.iterator');
+
+module.exports = parent;

node_modules/core-js/stable/set/intersection.js

@@ -0,0 +1,4 @@
+'use strict';
+var parent = require('../../es/set/intersection');
+
+module.exports = parent;

node_modules/core-js/stable/set/is-disjoint-from.js

@@ -0,0 +1,4 @@
+'use strict';
+var parent = require('../../es/set/is-disjoint-from');
+
+module.exports = parent;

node_modules/core-js/stable/set/is-subset-of.js

@@ -0,0 +1,4 @@
+'use strict';
+var parent = require('../../es/set/is-subset-of');
+
+module.exports = parent;

node_modules/core-js/stable/set/is-superset-of.js

@@ -0,0 +1,4 @@
+'use strict';
+var parent = require('../../es/set/is-superset-of');
+
+module.exports = parent;

node_modules/core-js/stable/set/symmetric-difference.js

@@ -0,0 +1,4 @@
+'use strict';
+var parent = require('../../es/set/symmetric-difference');
+
+module.exports = parent;

node_modules/core-js/stable/set/union.js

@@ -0,0 +1,4 @@
+'use strict';
+var parent = require('../../es/set/union');
+
+module.exports = parent;