[AFR] Implementing Class enchantments (ready for review) (#7992)

* [AFR] Implemented Druid Class

* [AFR] Implemented Wizard Class

* [AFR] Implemented Cleric Class

* [AFR] Implemented Fighter Class

* reworked class ability implementation

* fixed an error with setting class level

* small reworking of class triggers

* added class level hint

* added tests

* small change

* added common class for reminder text

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

@@ -0,0 +1,88 @@
+package mage.abilities.keyword;
+
+import mage.abilities.Ability;
+import mage.abilities.ActivatedAbilityImpl;
+import mage.abilities.costs.mana.ManaCostsImpl;
+import mage.abilities.effects.OneShotEffect;
+import mage.constants.Outcome;
+import mage.constants.TimingRule;
+import mage.constants.Zone;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+import mage.game.permanent.Permanent;
+
+import java.util.UUID;
+
+/**
+ * @author TheElk801
+ */
+public class ClassLevelAbility extends ActivatedAbilityImpl {
+
+    private final int level;
+    private final String manaString;
+
+    public ClassLevelAbility(int level, String manaString) {
+        super(Zone.BATTLEFIELD, new SetClassLevelEffect(level), new ManaCostsImpl<>(manaString));
+        this.level = level;
+        this.manaString = manaString;
+        setTiming(TimingRule.SORCERY);
+    }
+
+    private ClassLevelAbility(final ClassLevelAbility ability) {
+        super(ability);
+        this.level = ability.level;
+        this.manaString = ability.manaString;
+    }
+
+    @Override
+    public ClassLevelAbility copy() {
+        return new ClassLevelAbility(this);
+    }
+
+    @Override
+    public String getRule() {
+        return manaString + ": Level " + level;
+    }
+
+    @Override
+    public ActivationStatus canActivate(UUID playerId, Game game) {
+        Permanent permanent = getSourcePermanentIfItStillExists(game);
+        if (permanent != null && permanent.getClassLevel() == level - 1) {
+            return super.canActivate(playerId, game);
+        }
+        return ActivationStatus.getFalse();
+    }
+}
+
+class SetClassLevelEffect extends OneShotEffect {
+
+    private final int level;
+
+    SetClassLevelEffect(int level) {
+        super(Outcome.Benefit);
+        this.level = level;
+    }
+
+    private SetClassLevelEffect(final SetClassLevelEffect effect) {
+        super(effect);
+        this.level = effect.level;
+    }
+
+    @Override
+    public SetClassLevelEffect copy() {
+        return new SetClassLevelEffect(this);
+    }
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        Permanent permanent = source.getSourcePermanentIfItStillExists(game);
+        if (permanent == null || !permanent.setClassLevel(level)) {
+            return false;
+        }
+        game.fireEvent(GameEvent.getEvent(
+                GameEvent.EventType.GAINS_CLASS_LEVEL, source.getSourceId(),
+                source, source.getControllerId(), level
+        ));
+        return true;
+    }
+}