[TOFIX] Relation Collection in entities: "Select ...." is required in One to Many case too



Currently, the “Select child types…” option appears only for many-to-many relationships but not for one-to-many relationships. But it is applicable for both cases so that users can select and add existing entities of the child type to the parent entity’s collection.

Also, the “Select child types…” label should comply with the Title Case of the type name and be “Select Child Types…”.