Added authentication and authorization, updated dependency injections, removed hard-coded connection string

SchengenVisaApi/ApplicationLayer/AuthServices/LoginService/ILoginService.cs

@@ -0,0 +1,12 @@
+using ApplicationLayer.AuthServices.Requests;
+
+namespace ApplicationLayer.AuthServices.LoginService
+{
+    /// Handles <see cref="UserLoginRequest"/>
+    public interface ILoginService
+    {
+        /// Handle <see cref="UserLoginRequest"/>
+        /// <returns>JWT-token</returns>
+        Task<string> LoginAsync(UserLoginRequest request, CancellationToken cancellationToken);
+    }
+}