## What does this PR do?
Fixes that it can happen that Round Robin host is booked outside of availability.
I found and fixed the following two scenarios where this can happen:
- when host has a date override
- when host is available for only a part the event time (for example, booking time 9:00-11:00 and user is only available between 10:00-11:00)
Fixes#10315Fixes#11690
It also fixes that it can happen that round robin doesn't correctly pick the luck user (least recently booked). This happened when a user was an attendee of a booking before, then we always compared this booking and never the actual last booking of this user.
## Type of change
- [x] Bug fix (non-breaking change which fixes an issue)
## How should this be tested?
#### Booked outside of availability:
1.
- Create Round Robin event and assign user1 and user2 as round robin hosts
- event duration: 120 minutes
- user 1 availability:
- Monday to Friday 9:00-17:00
- user2 availability:
- Monday to Friday 10:00-17:00
- Book event at a 9:00 slot -> check if i user1 is booked
- Book event again at a 9:00 slot -> check if user1 is booked again (user2 is not available at that time)
2.
- Change availability of user2
- Mark Monday as unavailable
- Add date override on any day this month
- Book any Monday this month -> see that user 1 is booked
- Again Book any Monday this month -> see that user 1 is booked again
#### Wrong lucky user
- Book event and add user1's email as the attendee email address
- Book several slots where both users should be available, and see that it alternates between user1 and user2 (before it ended up always booking user1)
## Mandatory Tasks
- [ ] Make sure you have self-reviewed the code. A decent size PR without self-review might be rejected.
