[feature] Allow users to change email addresses without the need for a validation email

[Gotos]

Is your feature request related to a problem ?

I'm running a very small instance for myself and some friends. On the instance, I don't have SMTP set up. Unfortunately, that means users on my instance can't change their email address without me having to look up the verification token in the DB or the logs.

Describe the solution you'd like.

I think the ideal solution would be to have a config flag that allows instance admins to disable the need for verification emails. If that flag was enabled, users could just change their email immediately.

Describe alternatives you've considered.

Potentially this could also be solved by checking if SMTP is set up. If it's not, users can just change email addresses without the need to verify the new address.

Or combined the two approaches: have a config flag that defaults to "verification not necessary" if SMTP is disabled/not set up but to "verification necessary" otherwise, allowing admins to explicitly enable or disable it to override the default.

A completely different approach could be to add an option to the CLI tool to allow admins to manually confirm email address changes, similar to gotosocial admin account confirm.

Additional context.

Just as additional context, to explain why I think changing one's email address is even useful when my instance can't send emails in the first place:

The email address of a user is also required for them to be able to log in. I'm still setting up accounts for my instance via CLI, so I have a maximum amount of control over who can or can't join my instance. But if I use the wrong email address for a user (I.e.: the user would prefer a different one) or if I make a typo (both of these happened to me already), it's complicated for me to change/rectify that. To me, it would be great if there was something to make it easier for me.

Totally a "me" problem, that's what I get for not making sure I set up the email addresses for new users correctly, this is likely not a big deal to others. So I absolutely get if this is a rather low priority for y'all to work on! :)