feat(traffic-flow): enhance country handling in flow analytics

- Introduced country-specific handling in traffic flow analytics, including new mappings for country nodes and edges.
- Added mock data for countries and their respective service paths to improve visualization in the Network Map.
- Updated the `countryName` function to utilize `Intl.DisplayNames` for better localization of country names.
- Enhanced tests to validate country handling and ensure accurate representation in flow analytics.

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/contracts/src/traffic-flow.ts

@@ -329,6 +329,9 @@ export const flowMapHopsDtoSchema = z.object({
   services: z.array(flowMapServiceDtoSchema).optional(),
   serviceEdges: z.array(flowMapServiceEdgeDtoSchema).optional(),
   servicePaths: z.array(flowMapServicePathDtoSchema).optional(),
+  countries: z.array(flowMapServiceDtoSchema).optional(),
+  countryEdges: z.array(flowMapServiceEdgeDtoSchema).optional(),
+  countryPaths: z.array(flowMapServicePathDtoSchema).optional(),
   mapServiceMinSharePct: z.number().min(0).max(100).optional(),
   dedupApplied: z.boolean(),
   excludeMeshApplied: z.boolean(),