Extend icarAnimalSortingCommandResource with milkshifts

[Harry-UA]

The sorting command has a validFrom property, but some systems can handle sorting based on milkshift. Maybe it would be nice to have a kind of an array where the milkshifts could be specified?

"milkShifts": [
1,
3,
],

In this example the animal should be sorted after milking 1 or milking 3.

[cookeac]

There are a few things to think about regarding sorting:

• Whether there should be sorting rules around animal set or other criteria (possibly this is something different)
• You may want to sort animals in milk shift 1 and 3 but not in the middle of the night in shift 2 - without shifts you would need 2 commands with different validity times.