aw6374: each year new calculation model; fix OM -> Carbon switch, calculation based on carbon

ICarbonCalculation.cs

@@ -0,0 +1,18 @@
+using CarbonService.Models;
+using FarmMapsAPI.Carbon.Models;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace FarmMapsAPI.Carbon
+{
+    public interface ICarbonCalculation
+    {
+        string Validate(CarbonRequest farmInput);
+        CarbonRequest MapFarmMapsToMiterra(FarmMapsCarbonRequest farmInput);
+        CarbonSummary Calculate(CarbonRequest farmInput);
+        double? GetCropYield(string cropCode, int year, int postalCode);
+    }
+}