Every call type can now book onto its own calendar and copy in whoever needs to be there

Each kind of meeting can send its invitation from a specific calendar instead of everything landing in one place, and can automatically add extra people to every invitation so they get a real calendar entry rather than just a heads-up email. Booking pages also share with a clearer preview that shows the call's name and what it is for, and other people's calendars can be connected purely to block busy time.