Feature Request: ActivityPub API login different user

### What

When logging into wordpress via the ActivityPub Authorize, the authorize page will pick the logged-in user.
The page offers to either Authorize or Cancel (which returns to the app url)
There isn't a great way to log in as a different user.

### Why

I use different author/actors for different purposes, and it currently requires opening another window to log out, before trying to authorize again.

### How

Perhaps an additional link/button to logout the current user, while keeping all the authorization parameters

Start at the WordPress ActivityPub Authorize page and trace how the current user and authorization parameters are handled. Check the existing login and logout flow first; done means a user can switch accounts from the authorization page and return to the app with all authorization parameters preserved.

Written by the indexing model from the issue text.