Add alerts for Create/Delete/Edit features

[hjusassac]

1. Confirm before execution
   • when yes, execute.
   • when no, do nothing.
2. Alert after execution
   • when successfully done, show success message and redirect to ??
   • when failed, remain at the page? or refresh page? hmm

• [ ] Add user(registration), challenge, place
• [ ] Delete user, challenge, place
• [ ] Edit user(my profile, admin), challenge