IAV-1211/add dynamic CORS origin support for widget paths
- Replace CorsWebFilter with custom WebFilter for fine-grained CORS control
- Add WidgetOriginService to fetch allowed origins from customer-care service
- Restrict dynamic origins to widget path prefix (/api/customer-care/agents/widget)
- Support configurable null origin handling (cors.allow-null-origin)
- Enable scheduling for periodic origin refresh (@EnableScheduling)