Bugfix: don't allow other players to move warships (#879)

## Description:
The MoveWarshipExecution now verifies that the player who requested to
move owns the warship. This prevents players from moving other players'
warships.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

evan

src/core/execution/ExecutionManager.ts

@@ -63,7 +63,7 @@ export class Executor {
       case "cancel_boat":
         return new BoatRetreatExecution(playerID, intent.unitID);
       case "move_warship":
-        return new MoveWarshipExecution(intent.unitId, intent.tile);
+        return new MoveWarshipExecution(player, intent.unitId, intent.tile);
       case "spawn":
         return new SpawnExecution(
           player.info(),