Is your feature request related to a problem? Please describe.
We should share more code between single, multi, hasOne, and hasMany resolver, a bit like we do for mutators.
We need to check that hasMany/hasOne cannot be resolved on field user is not allowed to read (normally it's the case already but this deserves a unit test on its own=
We need to filter the list of documents user can read in relations, mainly when the permission is "owners", this is not the case yet (we however filter fields correctly in the related document)
Is your feature request related to a problem? Please describe.