Refactor Api-Client

Add Exceptionhandler, AlertService JSON-Converter
AppSettings via DI

Reformat Code

Jugenddienst Stunden/Types/NominalDay.cs

@@ -1,7 +1,8 @@
 namespace Jugenddienst_Stunden.Types;
-internal class NominalDay {
+
+public class NominalDay {
 	public int day_number;
 	public int month_number;
 	public double hours;
 	public DateOnly date;
-}
+}