Inital work on breaking out the core logic out of the MVC API Web App in preparation to migrating to minimal API's in a seperate project

AS1024.GeoFeed.Core/Tools/GeoFeedTools.cs

@@ -0,0 +1,20 @@
+using AS1024.GeoFeed.Models;
+using System.Text;
+
+namespace AS1024.GeoFeed.Core.Tools
+{
+    public static class GeoFeedTools
+    {
+        public static string ToGeoFeedCsv(this List<IPGeoFeed> geoFeeds)
+        {
+            StringBuilder csvContent = new();
+
+            foreach (IPGeoFeed feed in geoFeeds)
+            {
+                csvContent.AppendLine($"{feed.Prefix},{feed.GeolocCountry},{feed.GeolocRegion},{feed.GeolocCity},{feed.GeolocPostalCode}");
+            }
+
+            return csvContent.ToString();
+        }
+    }
+}