Add dropdown for selecting groups

Summary: This diff refactors the group selection to the dropdown. As with the growing list of grps, dropdown will be easy to search and scale

Reviewed By: mweststrate

Differential Revision: D21175998

fbshipit-source-id: 90f1a81dfc6c2232cd2dcf767ed01205fc63e1fd

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

@@ -0,0 +1,20 @@
+/**
+ * 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 View from './View';
+import {colors} from './colors';
+
+const Line = styled(View)<{color?: string}>(({color}) => ({
+  backgroundColor: color ? color : colors.greyTint2,
+  height: 1,
+  width: 'auto',
+  flexShrink: 0,
+}));
+export default Line;