Rework AsThough handling to allow choosing/affecting a specific alternate cast (#11114)

* Rework AsThoughEffect

* some cleanup of MageIdentifer

* refactor ActivationStatus

* fix bolas's citadel

* fix a couple of the Alternative Cost being applied too broadly.

* fix Risen Executioneer

* allow cancellation of AsThough choice.

* fix One with the Multiverse

* cleanup cards needing their own MageIdentifier

* last couple of fixes

* apply reviews for cleaner code.

* some more cleanup

Mage/src/main/java/mage/game/events/GameEvent.java

@@ -716,7 +716,7 @@ public class GameEvent implements Serializable {
         if (approvingObject == null) {
             return false;
         }
-        if (identifier == null) {
+        if (identifier.equals(MageIdentifier.Default)) {
             return false;
         }
         return identifier.equals(approvingObject.getApprovingAbility().getIdentifier());