Add ToString overrides for orders

MultiversalDiplomacy/Orders/ConvoyOrder.cs

@@ -34,4 +34,9 @@ public class ConvoyOrder : UnitOrder
         this.Season = season;
         this.Location = location;
     }
+
+    public override string ToString()
+    {
+        return $"{this.Unit} convoys {this.Target} -> {this.Province} {this.Season}";
+    }
 }

MultiversalDiplomacy/Orders/HoldOrder.cs

@@ -9,4 +9,9 @@ public class HoldOrder : UnitOrder
 {
     public HoldOrder(Power power, Unit unit)
         : base (power, unit) {}
+
+    public override string ToString()
+    {
+        return $"{this.Unit} holds";
+    }
 }

MultiversalDiplomacy/Orders/MoveOrder.cs

@@ -34,6 +34,11 @@ public class MoveOrder : UnitOrder
         this.Location = location;
     }
 
+    public override string ToString()
+    {
+        return $"{this.Unit} -> {this.Province} {this.Season}";
+    }
+
     /// <summary>
     /// Returns whether another move order is in a head-to-head battle with this order.
     /// </summary>

MultiversalDiplomacy/Orders/SupportHoldOrder.cs

@@ -11,4 +11,9 @@ public class SupportHoldOrder : SupportOrder
         : base (power, unit, target)
     {
     }
+
+    public override string ToString()
+    {
+        return $"{this.Unit} supports {this.Target}";
+    }
 }

MultiversalDiplomacy/Orders/SupportMoveOrder.cs

@@ -34,6 +34,11 @@ public class SupportMoveOrder : SupportOrder
         this.Location = location;
     }
 
+    public override string ToString()
+    {
+        return $"{this.Unit} supports {this.Target} -> {this.Province} {this.Season}";
+    }
+
     public bool IsSupportFor(MoveOrder move)
         => this.Target == move.Unit
         && this.Season == move.Season