flipper-server refactor

Summary:
This changes moves most of the functionality found in flipper-server to flipper-server-core.

flipper-server will mostly be a package that wraps around flipper-server-core. Staying in flipper-server:
- Command line args
- Orchestration to start the necessary servers

Reviewed By: aigoncharov

Differential Revision: D36807087

fbshipit-source-id: f29002c7cc5d08b8c5184fdaaa02ba22562a9f45

desktop/flipper-server-core/src/gk.tsx

@@ -0,0 +1,21 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import GKImplementation from './fb-stubs/GK';
+
+let loaded = false;
+
+export function getGatekeepers(username: string): Record<string, boolean> {
+  if (!loaded) {
+    // this starts fetching gatekeepers, note that they will only be available on next restart!
+    GKImplementation.init(username);
+    loaded = true;
+  }
+  return GKImplementation.allGKs();
+}