new workflow Terminate of Studierendenantrag

- DB Update for new studierendenantrag_statustyp with studierendenantrag_statustyp_kurzbz = 'Storniert'
- new permission student/studierendenantrag
- possibility to set status to Terminated in case of new permission

public/js/api/factory/studstatus/leitung.js

@@ -96,5 +96,12 @@ export default {
 			url: '/api/frontend/v1/studstatus/leitung/denyObjection',
 			params: antrag
 		};
-	}
+	},
+	terminate(antrag) {
+		return {
+			method: 'post',
+			url: '/api/frontend/v1/studstatus/leitung/terminateAntrag',
+			params: antrag
+		};
+	},
 };