front: use OperationalPointIdentifier instead of OperationalPointReference when it's posible

[younesschrifi]

This function takes an OperationalPointReference as input, but it never needs/uses anything from the track field. It would make more sense to take an OperationalPointIdentifier as input in my opinion. (This probably applies to other functions too.)

But let's leave this for another PR.

Originally posted by @emersion in #13789 (comment)