fix: refs #8612 handled duplicate code error in shelving & parking

loopback/locale/en.json

@@ -258,5 +258,6 @@
     "clonedFromTicketWeekly": ", that is a cloned sale from ticket {{ ticketWeekly }}",
 	"negativeReplaced": "Replaced item [#{{oldItemId}}]({{{oldItemUrl}}}) {{oldItem}} with [#{{newItemId}}]({{{newItemUrl}}}) {{newItem}} from ticket [{{ticketId}}]({{{ticketUrl}}})",
   	"The tag and priority can't be repeated": "The tag and priority can't be repeated",
-	"duplicateWarehouse": "The introduced warehouse already exists"
+	"duplicateWarehouse": "The introduced warehouse already exists",
+	"duplicateCode": "The code already exists"
 }

loopback/locale/es.json

@@ -399,5 +399,6 @@
 	"Price cannot be blank": "El precio no puede estar en blanco",
 	"clonedFromTicketWeekly": ", que es una linea clonada del ticket {{ticketWeekly}}",
 	"negativeReplaced": "Sustituido el articulo [#{{oldItemId}}]({{{oldItemUrl}}}) {{oldItem}} por [#{{newItemId}}]({{{newItemUrl}}}) {{newItem}} del ticket [{{ticketId}}]({{{ticketUrl}}})",
-    "duplicateWarehouse": "El almacén seleccionado ya existe en la zona"
+	"duplicateWarehouse": "El almacén seleccionado ya existe en la zona",
+	"duplicateCode": "El código ya existe"
 }

modules/shelving/back/models/parking.js

@@ -0,0 +1,5 @@
+module.exports = Self => {
+    Self.validatesUniquenessOf('code', {
+        message: `duplicateCode`
+    });
+};

modules/shelving/back/models/shelving.js

@@ -1,4 +1,8 @@
 module.exports = Self => {
     require('../methods/shelving/getSummary')(Self);
     require('../methods/shelving/addLog')(Self);
+
+    Self.validatesUniquenessOf('code', {
+        message: `duplicateCode`
+    });
 };