Re-use pkg-lib for runtime plugin compilation

Summary: Re-use the same function for plugin building both at publishing time by "flipper-pkg" and in runtime by Flipper itself.

Reviewed By: jknoxville

Differential Revision: D21129685

fbshipit-source-id: b7bff6737310352d28a14223128f127ac4d2eebf

desktop/static/index.js

@@ -8,7 +8,6 @@
  */
 
 global.electronRequire = require;
-global.electronResolve = require.resolve;
 global.electronProcess = process;
 
 require('./main.bundle.js');