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/fast-stable-stringify/test/validate.js

@@ -0,0 +1,24 @@
+var assert = require('assert');
+var eachRecursive = require('../util/eachRecursive');
+var jsonStableStringify = require('json-stable-stringify');
+var input = require('../fixtures').input;
+
+/**
+ * Assumes json-stable-stringify is always right.
+ * @param {function(*):string} stringify
+ */
+module.exports = function validateLibOutput(stringify) {
+	var numComparisons = 0;
+	eachRecursive(input, function (val, path) {
+		var mine = stringify(val);
+		var expectedVal = jsonStableStringify(val);
+		if (mine !== expectedVal) {
+			console.log('expected', expectedVal);
+			console.log('actual', mine);
+			global.value = val;
+		}
+		assert.equal(mine, expectedVal);
+		numComparisons++;
+	});
+	assert.equal(numComparisons, 569);
+};