Move DetailSidebar to flipper-plugin

Summary: This moves `<DetailSidebar>` component to `flipper-plugin` and documents it. No semantic changes.

Reviewed By: passy

Differential Revision: D27234575

fbshipit-source-id: 74640602d718f84ad999f5dac0420089796ed7fb

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

@@ -0,0 +1,27 @@
+/**
+ * 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 React from 'react';
+import {tryGetFlipperLibImplementation} from '../plugin/FlipperLib';
+import {Layout} from './Layout';
+
+export type DetailSidebarProps = {
+  children: any;
+  width?: number;
+  minWidth?: number;
+};
+
+/* eslint-disable react-hooks/rules-of-hooks */
+export function DetailSidebar(props: DetailSidebarProps) {
+  const lib = tryGetFlipperLibImplementation();
+  if (lib?.DetailsSidebarImplementation) {
+    return <lib.DetailsSidebarImplementation {...props} />;
+  }
+  return <Layout.Container>{props.children}</Layout.Container>;
+}