refactor: reorganize Application layer into folder structure

src/GreenHome.Application/Interfaces/IAlertService.cs

@@ -0,0 +1,7 @@
+namespace GreenHome.Application;
+
+public interface IAlertService
+{
+    Task<AlertCheckResult?> CheckAndSendAlertsAsync(int deviceId, TelemetryDto telemetry, CancellationToken cancellationToken);
+    Task SendPowerOutageAlertAsync(int deviceId, CancellationToken cancellationToken);
+}