New config option to allow teleporting users to spawn when their jail time expires

[baailey]

Currently, the only config option related to a user being TP'd out of jail is teleport-back-when-freed-from-jail. This option when set to true will teleport a user back to where they were before a jail, which I personally find inconvenient for situations where a user is jailed for xray. It'll simply teleport them back to the mine they were jailed for.

If you set this option to false, the user will remain in jail until they themselves teleport out with /spawn, /home etc (whatever the server allows them access to), which is another inconvenience if the user does not know this is an option. Can we set up signs / holos etc to let a user know about this? Yes. However, that could also not fit the theme of certain jails.

So, I propose a new config option (or changing the behaviour of the false toggle for teleport-back-when-freed-from-jail) that will automatically send users to spawn when their jail time expires.

[JRoy]

Will be added in #4132