Create task: Assign default workers

When creating a task, it is now possible to send assign_default_workers parameter.

If the param is sent as true, we prioritize default workers set at the template level. If template level default workers do not exist, we will use the department level. Both are set per property.

Default assignees will be adjacent to assignments that were manually set. So if you send custom assignments, and also send assign_default_workers=true we will honor both.