fix(recognitions): optional date submission

recognitions-ifi.yaml

@@ -1783,7 +1783,14 @@ nodes:
                     translations:
                       en-eu: "In case of an ungraded course please enter “BE”."
             "datum": &datum-form-vhb
-              - "3": *datum-field
+              - "3":
+                  <<: *datum-field
+                  tooltip:
+                    fallback: "Datum (sofern auf dem Bescheid angegeben)"
+                    fallback-lang: de-de-formal
+                    translations:
+                      en-eu: "Date (if stated on the certificate)"
+                  optional: true
             "zertifikat": &zertifikat-form
               - "4": &zertifikat-field
                   tag: file