Return focal point in Delivery API reflecting backoffice

[bjarnef]

Follow-up on #18711 (comment)

Currently I think it is inconsistent that focal point isn't returned if in center (default location at 0.5, 0.5).

Especially because MediaPicker allow to configure whether focal point should be enabled or not. Even though in center, I don't see a reason why it shouldn't be returned.
Furthermore if it is possible to override (or hack) default location to not be in center, I think this can have unexpected side-effect.

We have in some headless projects enabled focal point for some media/image pickers and for other instancs not, but when focal point is in center (hidden when not enabled), there is not way based on Delivery API data to know the difference as is just return null in both cases.

Some may prefer to handle on fly crop in a specific way (default or fallback) or use CSS e.g. as a cover image... or some special calculation e.g. via JavaScript.

Summa summarum, if focal point is shown in backoffice, I will argue the focal point data should be returned in Delivery API.