Created a generalservice for helper methods.

Moved constants to Farmmaps API project.

FarmmapsApiSamples/NitrogenService.cs

@@ -150,7 +150,7 @@ namespace FarmmapsApiSamples
             {
                 _logger.LogInformation("Checking shapetogeotiff task status");
                 var itemTaskStatus = await _farmmapsApiService.GetTaskStatusAsync(isariaShapeItem.Code, taskCode);
-                if (itemTaskStatus.State == ItemTaskState.Error || itemTaskStatus.State == ItemTaskState.Ok)
+                if (itemTaskStatus.IsFinished)
                     tokenSource.Cancel();
             });