Fix get comments children

src/main/kotlin/fr/dcproject/entity/Comment.kt

@@ -38,4 +38,4 @@ open class Comment<T : TargetI>(
 
 open class CommentRef(id: UUID = UUID.randomUUID()) : CommentS(id)
 
-sealed class CommentS(id: UUID) : UuidEntity(id)
+sealed class CommentS(id: UUID) : TargetRef(id)

src/main/kotlin/fr/dcproject/entity/Extra.kt

@@ -42,9 +42,7 @@ interface TargetI : UuidEntityI {
         fun getReference(t: TargetI): String {
             val ref = this.getReference(t::class)
             return if (t is ExtraI<*>) {
-                ref +
-                        "_on_" +
-                        t.target.reference
+                "${ref}_on_${t.target.reference}"
             } else {
                 ref
             }