Absences API - Additional fields in the 'Hourly Absence Period' endpoint GET/POST responses

Three new fields are added to the hourly absence GET/POST response as follows:

1. 'timezone': as the start and end fields are returned in UTC timezone, so this field shows the timezone which was used to create the period
2. 'absence_type: attributes: time_off_type_id' - The numeric id of the absence type which is required for creating daily and hourly absence periods
3. 'absence_type: attributes: name' - Absence type name