Remove babel transforms for flipper-server

Summary: Flipper server itself requires no babel transforms. We applied extra transforms only for the bundled plugins. However, we pack and ship all plugins in the /static folder. They are always available on the FS. Therefore we could stop bundling any plugins into flipper-server's source code.

Reviewed By: lblasa

Differential Revision: D38910251

fbshipit-source-id: b3e9fe5ae2ab69ce5579b01b6793ebf7e88baf66

desktop/flipper-server-core/src/plugins/fb-stubs/pluginMarketplaceAPI.tsx

@@ -8,6 +8,7 @@
  */
 
 import {FlipperServer, MarketplacePluginDetails} from 'flipper-common';
+import fetch from 'node-fetch';
 
 export async function loadAvailablePlugins(
   server: FlipperServer,