Fix casting Transformed (#10778)

* Combine casting Transformed into a shared SpellAbility, apply transform effect before spell is cast

* Minor cleanup

* Use effect.apply() rather than game.applyEffects()

* Add test with Maskwood Nexus

Mage/src/main/java/mage/game/stack/Spell.java

@@ -774,7 +774,7 @@ public class Spell extends StackObjectImpl implements Card {
 
     @Override
     public Card getSecondCardFace() {
-        return null;
+        return card.getSecondCardFace();
     }
 
     @Override