Refactor: private fields and performance tweaks (#9625)

1a. Make `costs`, `manaCosts`, and `manaCostsToPay` private in `AbilityImpl` with access through getters/setters 
1b. fix cost adjuster for imprinted cards affected by the above

2a. Lazy instantiation for rarely used `data` field in `TargetPointerImpl`

3a. Pre-allocate certain array sizes in `Modes` and `CostsImpl`

4a. Make `manaTemplate` private in `BasicManaEffect`, copy when passing outside the class 
4b. Don't copy `manaTemplate` in copy constructor since it doesn't change 
4c. Add comments explaining copy usage for `manaTemplate` 
4d. Remove redundant variable assignment and make fields final 

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Co-authored-by: xenohedron <xenohedron@users.noreply.github.com>

Mage/src/main/java/mage/abilities/keyword/EchoAbility.java

@@ -37,7 +37,7 @@ public class EchoAbility extends TriggeredAbilityImpl {
         super(Zone.BATTLEFIELD, new EchoEffect(amount), false);
         this.amount = amount;
         this.echoPaid = false;
-        this.echoCosts.add(costs);
+        this.echoCosts.add(getCosts());
         this.lastController = null;
         this.manaEcho = true;
         this.rule = rule;