Fix fetch property config override regression

The commit done for NXP-26038 defeats the purpose of the work done for NXP-25512 in order to be able to do not fetch all properties of a document.

Which can just screw performances when it comes to browsing a document which has a big amount of fields referencing other objects/entities.

Note that https://github.com/nuxeo/nuxeo-web-ui/commit/41f9ffd3a53957e7376d569e7404a5ea4932a1a0#diff-a49119c35e2a5925fd6285a8019f90e1L24 also turns this conf property as a list. It was not intended to be a list...

At this point, maybe we should exhaustively list the property to be fetched by default (dc:creator, dc:lastContributors, dc:nature, dc:coverage, dc:subjects, etc.).
This way, we are sure that it is optimized whatever doc types are created in projects. But it means we'll need solid upgrade notes to tell that configuration must be added and ideally, studio should generate the needed config (which seems too late for 10.3)