Handle users using invite link twice

[ydennisy]

It is often the case that users will click the invite link twice, maybe for the purpose of finding the URL of the app again.

When clicking the link the second time a generic error is provided Confirmation token not found.

I would like to suggest to provide a specific error message Confirmation token previously confirmed, so that the application can handle this properly and navigate the user to login.

Discussion in supabase https://github.com/supabase/supabase/discussions/6004

cc @burggraf