[fidldev] Update paths - Update go test targets - Update fidlc build command Test: python3 $FIDLMISC_DIR/fidldev/fidldev_test.py -b Change-Id: Idd4ac62162f1c4c4d156229e7da6e28b592cb9b5 Reviewed-on: https://fuchsia-review.googlesource.com/c/fidl-misc/+/432214 Reviewed-by: Yifei Teng <yifeit@google.com>