lay ground work for supporting thargoid combat zones

EliteBGS/MainWindow.xaml.cs

@@ -285,7 +285,7 @@ public partial class MainWindow : Window {
             return;
         }
 
-        transaction.Grade = CombatZone.DifficultyLow;
+        transaction.Grade = CombatZones.DifficultyLow;
         RefreshView();
     }
 
@@ -295,7 +295,7 @@ public partial class MainWindow : Window {
             return;
         }
 
-        transaction.Grade = CombatZone.DifficultyMedium;
+        transaction.Grade = CombatZones.DifficultyMedium;
         RefreshView();
     }
 
@@ -305,7 +305,7 @@ public partial class MainWindow : Window {
             return;
         }
 
-        transaction.Grade = CombatZone.DifficultyHigh;
+        transaction.Grade = CombatZones.DifficultyHigh;
         RefreshView();
     }
 
@@ -315,7 +315,7 @@ public partial class MainWindow : Window {
             return;
         }
 
-        transaction.Type = CombatZone.GroundCombatZone;
+        transaction.Type = CombatZones.GroundCombatZone;
         RefreshView();
     }
 
@@ -325,7 +325,7 @@ public partial class MainWindow : Window {
             return;
         }
 
-        transaction.Type = CombatZone.ShipCombatZone;
+        transaction.Type = CombatZones.ShipCombatZone;
         RefreshView();
     }