New multi app supporting sidebar navigation

Summary:
This diff changes the sidebar navigation, fixing a bunch of issues:
It will be possible to quickly switch again between the same plugins in multiple apps
No need to expand-and-check the app dropdown until the app is connected
No need for ugly fallback selections if some app connects faster than another one

Reviewed By: nikoant

Differential Revision: D19272701

fbshipit-source-id: 10f5fab42391014ef4a4a4c91c529d93f8bfb125

src/test-utils/createMockFlipperWithPlugin.tsx

@@ -111,6 +111,7 @@ export async function createMockFlipperWithPlugin(
       selectedPlugin: pluginClazz.id,
       selectedApp: client.query.app,
       deepLinkPayload: null,
+      selectedDevice: device,
     }),
   );