[Feature Request] Add ability to log out of tcld (to be able to rechoose an email)

[k24dizzle]

Context: I accidentally clicked on the wrong email when initially logging in, then I had permission denied errors when I tried running commands. When I tried relogging in, it would just direct me to the device confirmation page without giving me the chance to correctly choose the right email.

Suggestion: There wasn't a straightforward way for me to use tcld to log out and reconnecting with a different email. Maybe introduce a tcld logout command.