Improved build-release open args
Improved build-release open args

Summary:
Improved `flipper:build-release` command with several options as suggested in earlier reviews. Flags added:

* `--npx` install using npx and start
* `--start` run directly from the build folder
* `--open` icmw previous two, spawn a browser

This should generally benefit developing from for example an on-demand server (although current socket access is currently only open to local host, so a port forward or remote entry point needs to be set up)

Reviewed By: antonk52

Differential Revision: D33308198

fbshipit-source-id: fb905647c8d9fbda9d3efc2bfdcbd4d03be84938

facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper