Include a collective's members list in the "Entidad" template

[PoeticaSonoraMX]

Whenever a collective is displayed in therda/entidadtemplate, show a list of its members, just as when an album's credits are displayed in the rda/serie template. The rule should be as follows: when an entity is classified as containing other entities, list all relationships between the collective entity and the individual ones before displaying available recordings for this entity in the repository.

The aim of this enhancement is to begin displaying relationships between entities, which at the moment are being entered by PSMX student members as a part of their editorialization activities, and stored in the repository but not available for the public.

[aureliomexa]

This list should be placed between the entity description and available recordings. Data to it fill out must be retrieved from entitytoentityrel. .