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/modules/es.string.from-code-point.js

@@ -0,0 +1,32 @@
+'use strict';
+var $ = require('../internals/export');
+var uncurryThis = require('../internals/function-uncurry-this');
+var toAbsoluteIndex = require('../internals/to-absolute-index');
+
+var $RangeError = RangeError;
+var fromCharCode = String.fromCharCode;
+// eslint-disable-next-line es/no-string-fromcodepoint -- required for testing
+var $fromCodePoint = String.fromCodePoint;
+var join = uncurryThis([].join);
+
+// length should be 1, old FF problem
+var INCORRECT_LENGTH = !!$fromCodePoint && $fromCodePoint.length !== 1;
+
+// `String.fromCodePoint` method
+// https://tc39.es/ecma262/#sec-string.fromcodepoint
+$({ target: 'String', stat: true, arity: 1, forced: INCORRECT_LENGTH }, {
+  // eslint-disable-next-line no-unused-vars -- required for `.length`
+  fromCodePoint: function fromCodePoint(x) {
+    var elements = [];
+    var length = arguments.length;
+    var i = 0;
+    var code;
+    while (length > i) {
+      code = +arguments[i++];
+      if (toAbsoluteIndex(code, 0x10FFFF) !== code) throw new $RangeError(code + ' is not a valid code point');
+      elements[i] = code < 0x10000
+        ? fromCharCode(code)
+        : fromCharCode(((code -= 0x10000) >> 10) + 0xD800, code % 0x400 + 0xDC00);
+    } return join(elements, '');
+  }
+});