Remove baton_id from team model

[redfast00]

The database model for team contains a baton_id; but this shouldn't be used (it should be calculated based on batonswitchovers). We should be able to remove this without any consequences; if anything breaks, this is a bug (since we then know this doesn't use the switchovers).

This is an easier issue than #134; we don't need to remove baton ID's entirely, just in the team model, which nobody should be using anyways.

[redfast00]

This is apparently also in use by monitoring; this edition, we should take care to always update the baton_id when we do a baton switchover; next edition, we should remove this from the database on the first codenight.