Add password validation to auth forms

[amorriscode]

Right now we don't actually have password strength validation. Supabase requires a password of 6 characters so we need to add that validation at the very least.

Right now if Supabase throws an error because the password isn't long enough, the user gets no information.

[idiglove]

I'd like to take this! Would be good to make my feet wet

[amorriscode]

That sounds great, thanks @idiglove!