*_one_of constraints in collections

[vkrasnovyd]

In the collection files it should be possible to define a list of fields, that will be checked together in the model-level constraint triggers. Depending on the trigger type, error should be raised if:

• maximum_one_of: More than one of the fields from the list is selected. Example:
  • motion: [lead_motion_id, diff_version]
• minimum_one_of: None of the fields from the list is selected. Example:
  • personal_note: [star, note]
• exactly_one_of: None or more than one of the fields from the list is selected. Examples:
  • poll_option: [meeting_user_id, text]
  • meeting_poll_default: [used_as_assignment_poll_config_in_meeting_id, used_as_motion_poll_config_in_meeting_id, used_as_topic_poll_config_in_meeting_id] (Note: these are view fields).