fix: improve loading on destination overview page

- Only load data from Contentstack
- Use static JSON for destination list
- Some logic improvements to data handling and types

apps/scandic-web/server/routers/contentstack/destinationOverviewPage/output.ts

@@ -25,7 +25,7 @@ export const blocksSchema = z.discriminatedUnion("__typename", [
 
 export const destinationOverviewPageSchema = z.object({
   destination_overview_page: z.object({
-    title: z.string(),
+    heading: z.string().nullish(),
     blocks: discriminatedUnionArray(blocksSchema.options),
     location: mapLocationSchema,
     system: systemSchema.merge(