Yarn workspaces

Summary:
1) moved "sonar/desktop/src" to "sonar/desktop/app/src", so "app" is now a separate package containing the core Flipper app code
2) Configured yarn workspaces with the root in "sonar/desktop": app, static, pkg, doctor, headless-tests. Plugins are not included for now, I plan to do this later.

Reviewed By: jknoxville

Differential Revision: D20535782

fbshipit-source-id: 600b2301960f37c7d72166e0d04eba462bec9fc1

desktop/app/src/ui/components/LoadingIndicator.tsx

@@ -0,0 +1,39 @@
+/**
+ * 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 styled from '@emotion/styled';
+import {keyframes} from 'emotion';
+
+const animation = keyframes({
+  '0%': {
+    transform: 'rotate(0deg)',
+  },
+  '100%': {
+    transform: 'rotate(360deg)',
+  },
+});
+
+const LoadingIndicator = styled.div<{size: number}>(props => ({
+  animation: `${animation} 1s infinite linear`,
+  width: props.size,
+  height: props.size,
+  minWidth: props.size,
+  minHeight: props.size,
+  borderRadius: '50%',
+  border: `${props.size / 6}px solid rgba(0, 0, 0, 0.2)`,
+  borderLeftColor: 'rgba(0, 0, 0, 0.4)',
+}));
+
+LoadingIndicator.displayName = 'LoadingIndicator';
+
+LoadingIndicator.defaultProps = {
+  size: 50,
+};
+
+export default LoadingIndicator;