feat(JoinResource3TiersService): add findAllRelations method

solidify-controller/src/main/java/ch/unige/solidify/service/JoinResource3TiersService.java

@@ -47,6 +47,18 @@ import ch.unige.solidify.specification.SolidifySpecification;
 public abstract class JoinResource3TiersService<T extends Resource, V extends Resource, W extends Resource, J extends JoinResource<?>>
         extends JoinResourceNTiersService<T, V, J> {
 
+  /**
+   * Find all relations in which the parent is involved
+   *
+   * @param parentId
+   * @return
+   */
+  public List<J> findAllRelations(String parentId) {
+    Join3TiersSpecification<J> specification = this.getJoinSpecification(parentId, null, null);
+    specification.setFilterOnChildResId(true);
+    return this.joinRepository.findAll(specification);
+  }
+
   /**
    * Find all relations between the parent and the child and any grandchildren
    *