PF - Hide role labels for "Non-Navigable" associations

[fabiovinci]

The PF data model includes associations that are navigable in one direction only, but the name, description, and multiplicity have still been added to the target role.

According to the outcomes of the two related TG change proposals (#123 and #126, it was decided to retain the roles in the association properties while hiding them in the diagram.

This solution will maintain clear documentation of roles associated with different feature types, helping to avoid confusion caused by their visibility in the UML diagram.

These updates will be implemented in the upcoming release scheduled for the end of January 2025.