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/sv/product.js

@@ -25,7 +25,8 @@ export default {
   "pickupPrice": "Avhämtningspris: 19,90 € per stickling.",
   "consistsOf": "Består av:",
   "loadingComponentDetails": "{{index}}. Laddar komponentdetaljer...",
-  "individualPriceTotal": "Total individuell pris:",
+  "loadingProduct": "Produkten laddas...",
+  "individualPriceTotal": "Total individuellt pris:",
   "setPrice": "Setpris:",
   "yourSavings": "Din besparing:",
   "similarProducts": "Liknande produkter",