[DMN Designer] Multiple DRDs Support - Show DRDs action flyout menu for DRD selection

Show DRDs action flyout menu for DRD selection:

⚠️ Notice:

• Before starting this JIRA, check with rhn-support-eclayton which action triggers this menu (right click, single click, etc), and revisit the icons (added be DROOLS-4780 and DROOLS-4779) to add the action that will trigger this flyout menu