Add ability to logout and thus turn a refresh token into a machine auth

[DoctorMcKay]

For WebBrowser logins, machine auths are only issued when you logout.

[akuma0]

Hi!
i work on it on my side too.
if i have some result i will post here.
The big problem is that we need to wait the cookie expiration to renew it... It's take sooooo long to test...

[akuma0]

Hi!
Here some news, i'm stuck on the first redirection, i need to send 2 new tokens : steamRefresh_steam & steamMachineAuth.
steamRefresh_steam it's ok we have the infos to create it, but steamMachineAuth, i don't know how to make it.
When i decode them, they are very similar.