Introduce Spinner and Dialog.loading

Summary: Per title

Reviewed By: nikoant

Differential Revision: D29790505

fbshipit-source-id: 7c995be59418ffd4c337eb8d1905bd2f2466e5cd

desktop/flipper-plugin/src/ui/Spinner.tsx

@@ -0,0 +1,18 @@
+/**
+ * Copyright (c) Facebook, Inc. and its 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 {LoadingOutlined} from '@ant-design/icons';
+import {Spin} from 'antd';
+import React from 'react';
+
+export function Spinner({size}: {size?: number}) {
+  return (
+    <Spin indicator={<LoadingOutlined style={{fontSize: size ?? 24}} spin />} />
+  );
+}