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/lodash/_unescapeHtmlChar.js

@@ -0,0 +1,21 @@
+var basePropertyOf = require('./_basePropertyOf');
+
+/** Used to map HTML entities to characters. */
+var htmlUnescapes = {
+  '&': '&',
+  '&lt;': '<',
+  '&gt;': '>',
+  '&quot;': '"',
+  '&#39;': "'"
+};
+
+/**
+ * Used by `_.unescape` to convert HTML entities to characters.
+ *
+ * @private
+ * @param {string} chr The matched character to unescape.
+ * @returns {string} Returns the unescaped character.
+ */
+var unescapeHtmlChar = basePropertyOf(htmlUnescapes);
+
+module.exports = unescapeHtmlChar;