Cleanup copy methods (#11038)

* remove System.out.println
* Card copy() covariant return
* Effect copy() covariant return
* Cost copy() covariant return
* Ability copy() covariant return
* ContinuousEffect copy() covariant return

Mage/src/main/java/mage/abilities/costs/OrCost.java

@@ -146,7 +146,7 @@ public class OrCost implements Cost {
     }
 
     @Override
-    public Cost copy() {
+    public OrCost copy() {
         return new OrCost(this);
     }
 }