feat: decide the staffing split per ski level

templates/admin/system/staffing_rule/_form.html.twig

@@ -3,8 +3,9 @@
     {{ form_row(form.productCode) }}
     {{ form_row(form.guides) }}
     {{ form_row(form.skiBeginner) }}
+    {{ form_row(form.splitBeginner) }}
     {{ form_row(form.skiAdvanced) }}
-    {{ form_row(form.split) }}
+    {{ form_row(form.splitAdvanced) }}
     {{ form_row(form.guiding) }}
     {{ form_row(form.enabled) }}
 </div>