Add services and controllers for games (#12)

Co-authored-by: Maxime Adler <madler@sqli.com>
Reviewed-on: #12

src/GameIdeas/GameIdeas.Shared/Exceptions/NotFoundException.cs

@@ -0,0 +1,3 @@
+namespace GameIdeas.Shared.Exceptions;
+
+public class NotFoundException(string msg, Exception? innerException = null) : Exception(msg, innerException);