Refactored and fixed errors

SchengenVisaApi/ApplicationLayer/VisaApplications/Handlers/IVisaApplicationsRequestHandler.cs

@@ -0,0 +1,11 @@
+using ApplicationLayer.VisaApplications.Requests;
+using Domains.VisaApplicationDomain;
+
+namespace ApplicationLayer.VisaApplications.Handlers;
+
+public interface IVisaApplicationsRequestHandler
+{
+    Task<List<VisaApplication>> Get(CancellationToken cancellationToken);
+
+    void HandleCreateRequest(VisaApplicationCreateRequest request, CancellationToken cancellationToken);
+}