Add EntityDeathEvent and implementations

src/main/java/emu/grasscutter/server/event/entity/EntityDeathEvent.java

@@ -0,0 +1,20 @@
+package emu.grasscutter.server.event.entity;
+
+import emu.grasscutter.game.entity.GameEntity;
+import emu.grasscutter.server.event.types.EntityEvent;
+import emu.grasscutter.utils.Location;
+import lombok.Getter;
+
+import javax.annotation.Nullable;
+
+public final class EntityDeathEvent extends EntityEvent {
+    @Getter private final Location deathLocation;
+    @Getter @Nullable private final GameEntity killer;
+
+    public EntityDeathEvent(GameEntity entity, int killerId) {
+        super(entity);
+
+        this.deathLocation = new Location(entity.getScene(), entity.getPosition());
+        this.killer = entity.getScene().getEntityById(killerId);
+    }
+}