[RN] Handle gracefully when an invalid devfile is found in a git repository

= Improved UX with invalid devfiles during workspace creation With this update, {prod-short} displays a warning for users in the *Creating a workspace* page that the devfile in the remote Git repository is invalid. The warning offers users two options: *Continue with the default devfile* or *Reload*. This feature is particularly useful when a user is editing and testing a devfile.