Move plugins to "sonar/desktop/plugins"

Summary:
Plugins moved from "sonar/desktop/src/plugins" to "sonar/desktop/plugins".

Fixed all the paths after moving.

New "desktop" folder structure:
- `src` - Flipper desktop app JS code executing in Electron Renderer (Chrome) process.
- `static` - Flipper desktop app JS code executing in Electron Main (Node.js) process.
- `plugins` - Flipper desktop JS plugins.
- `pkg` - Flipper packaging lib and CLI tool.
- `doctor` - Flipper diagnostics lib and CLI tool.
- `scripts` - Build scripts for Flipper desktop app.
- `headless` - Headless version of Flipper desktop app.
- `headless-tests` - Integration tests running agains Flipper headless version.

Reviewed By: mweststrate

Differential Revision: D20344186

fbshipit-source-id: d020da970b2ea1e001f9061a8782bfeb54e31ba0

desktop/plugins/layout/ToolbarIcon.tsx

@@ -0,0 +1,41 @@
+/**
+ * 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 {Glyph, styled, colors} from 'flipper';
+import React from 'react';
+
+type Props = {
+  title: string;
+  icon: string;
+  active: boolean;
+  onClick: () => void;
+};
+
+const ToolbarIcon = styled.div({
+  marginRight: 9,
+  marginTop: -3,
+  marginLeft: 4,
+  position: 'relative', // for settings popover positioning
+});
+
+export default function(props: Props) {
+  return (
+    <ToolbarIcon onClick={props.onClick} title={props.title}>
+      <Glyph
+        name={props.icon}
+        size={16}
+        color={
+          props.active
+            ? colors.macOSTitleBarIconSelected
+            : colors.macOSTitleBarIconActive
+        }
+      />
+    </ToolbarIcon>
+  );
+}