Complex fields required inputs behavior

[kosarko]

On the topic of complex fields...I don't think the required flag behaves as it should; the requirements are not enforced if the whole field is not mandatory (it seems).

Funding is an optional field, but if someone decides to fill it in, they should succeed only if they fill in all the inputs marked as required. Or with size info...you need both the number and the unit and that's independent on whether local.size.info is mandatory or not.

Originally posted by @kosarko in https://github.com/ufal/clarin-dspace/issues/1083#issuecomment-2085582523