recordRepresentation prop not working

[KDederichs]

API Platform version(s) affected: 3.4.3

Description
According to https://marmelab.com/react-admin/Tutorial.html#handling-relationships there's a recordRepresentation that's used to display an actual readable name on linked resources. You guys have the prop as well but it's doing nothing, so I'd say either get rid of it or implement it as well

How to reproduce
Set recordRepresentation prop on ResourceGuesser, see that it's still the ID