----------------------Issue--------------------------
When calling get_work_duration_data on a calendar that contains adjacent calendar attendances,
we get a traceback in the method _get_attendance_intervals_days_data.
This is due to the fact that adjacent attendances (like 09:00 -> 13:00, 13:00 -> 17:00) will get merged into one single interval.
Which will generate an attendance interval with multiple resource.calendar.attendance records associated with it.
----------------Steps to reproduce-------------------
1) Create a Calendar
2) Create for a same day 2 attendances going from 09:00 to 13:00 and another going from 13:00 to 17:00 3) Try creating a time-off for that day
3) Associate that calendar with an employee
4) Try creating a time off on the day where we have adjacent attendances
---------------------Fix-----------------------------
Adapt _get_attendance_intervals_days_data to handle attendance intervals associated with multiple resource.calendar.attendance
task-3615723
closesodoo/odoo#144036
Signed-off-by: Bertrand Dossogne (bedo) <bedo@odoo.com>