Resend confirmation email should get some kind of feedback

If you click the link it works, but there's no feedback. There should be something

@bufke Should we think about this one in a broader sense? I mean, we could just put "Sent!" as a bit of inline text right next to the link as a one-off. Or we can integrate the message box up top to look like the messaging above the login/register forms as a one-off. Or we can think about some kind of global toast-snackbar-ish thing and make this the first place we use it.

Basically, we need to decide how much time we want to spend on this now in relation to other tasks, and it'll determine the direction for this issue.