Added validation for the number of characters in the name of the receipt

frontend/language/src/nb.json

@@ -613,6 +613,7 @@
   "process_editor.configuration_panel_custom_receipt_heading": "Opprett din egen kvittering",
   "process_editor.configuration_panel_custom_receipt_info": "Hvis du heller vil lage din egen kvittering, kan du opprette den her. Kvitteringen du lager selv vil overstyre standardkvitteringen.",
   "process_editor.configuration_panel_custom_receipt_layout_set_name": "Navn på sidegruppe: ",
+  "process_editor.configuration_panel_custom_receipt_layout_set_name_validation": "Navnet må ha minst 2 tegn",
   "process_editor.configuration_panel_custom_receipt_navigate_to_lage_button": "Gå til Lage",
   "process_editor.configuration_panel_custom_receipt_navigate_to_lage_title": "Gå til Lage for å utforme kvitteringen din",
   "process_editor.configuration_panel_custom_receipt_select_data_model_label": "Datamodellknytning",

frontend/packages/shared/src/utils/layoutSetsUtils.ts

@@ -15,6 +15,8 @@ export const getLayoutSetIdValidationErrorKey = (
   if (oldLayoutSetId === newLayoutSetId) return null;
   if (!validateLayoutNameAndLayoutSetName(newLayoutSetId)) return 'ux_editor.pages_error_format';
   if (!newLayoutSetId) return 'validation_errors.required';
+  if (newLayoutSetId.length === 1)
+    return 'process_editor.configuration_panel_custom_receipt_layout_set_name_validation';
   if (layoutSets.sets.some((set) => set.id === newLayoutSetId))
     return 'process_editor.configuration_panel_layout_set_id_not_unique';
   return null;