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/eslint/lib/unsupported-api.js

@@ -0,0 +1,30 @@
+/**
+ * @fileoverview APIs that are not officially supported by ESLint.
+ *      These APIs may change or be removed at any time. Use at your
+ *      own risk.
+ * @author Nicholas C. Zakas
+ */
+
+"use strict";
+
+//-----------------------------------------------------------------------------
+// Requirements
+//-----------------------------------------------------------------------------
+
+const { FileEnumerator } = require("./cli-engine/file-enumerator");
+const { FlatESLint, shouldUseFlatConfig } = require("./eslint/flat-eslint");
+const FlatRuleTester = require("./rule-tester/flat-rule-tester");
+const { ESLint } = require("./eslint/eslint");
+
+//-----------------------------------------------------------------------------
+// Exports
+//-----------------------------------------------------------------------------
+
+module.exports = {
+    builtinRules: require("./rules"),
+    FlatESLint,
+    shouldUseFlatConfig,
+    FlatRuleTester,
+    FileEnumerator,
+    LegacyESLint: ESLint
+};