Expose more meta information for plugins

Summary: expose `appName`, `appId` and `device` to Sandy plugins. Will be used in next diff to migrate navigation plugin

Reviewed By: cekkaewnumchai

Differential Revision: D24857253

fbshipit-source-id: 03ac3d376d5d1950bcf3d78386a65ce167b517e3

desktop/flipper-plugin/src/__tests__/test-utils.node.tsx

@@ -56,6 +56,9 @@ test('it can start a plugin and lifecycle events', () => {
   expect(instance.deactivateStub).toBeCalledTimes(2);
   expect(instance.destroyStub).toBeCalledTimes(1);
 
+  expect(instance.appName).toBe('TestApplication');
+  expect(instance.appId).toBe('TestApplication#Android#TestDevice#serial-000');
+
   // cannot interact with destroyed plugin
   expect(() => {
     p.connect();