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

SchengenVisaApi/Infrastructure/Common/DateTimeProvider.cs

@@ -0,0 +1,10 @@
+using ApplicationLayer.GeneralNeededServices;
+
+namespace Infrastructure.Common
+{
+    /// Implements <see cref="IDateTimeProvider"/>
+    public class DateTimeProvider : IDateTimeProvider
+    {
+        DateTime IDateTimeProvider.Now() => DateTime.Now;
+    }
+}