feat(SEO): enhance product and category JSON-LD with shipping and return policy details

- Added merchant return policy and shipping details to the JSON-LD for both product and category schemas.
- Updated delivery method price to reflect the new shipping rate of 5.90 €.
- Improved localization files to include loading messages for products and updated various translations for consistency.

src/i18n/locales/it/delivery.js

@@ -16,9 +16,9 @@ export default {
   "prices": {
     "free": "gratis",
     "freeFrom100": "(gratis da 100€)",
-    "dhl": "6,99 €",
-    "dpd": "4,90 €",
-    "sperrgut": "28,99 €"
+    "dhl": "5.90 €",
+    "dpd": "4.90 €",
+    "sperrgut": "28.99 €"
   },
   "times": {
     "cutting14Days": "Tempi di consegna: 14 giorni",