override Equals with check if lat and lon are equal

OSMDatastructure/Coordinates.cs

@@ -46,5 +46,17 @@ namespace OSMDatastructure
         {
             return string.Format("{0} {1}", this.lat.ToString(CultureInfo.InvariantCulture), this.lon.ToString(CultureInfo.InvariantCulture));
         }
+
+        public override bool Equals(object? obj)
+        {
+            if (obj != null && obj.GetType() == this.GetType())
+            {
+                Coordinates objconv = (Coordinates)obj;
+                if (objconv.lat.Equals(this.lat) && objconv.lon.Equals(this.lon))
+                    return true;
+            }
+
+            return false;
+        }
     }
 }