Delete quests from the player if there are errors loading them from the db

src/main/java/emu/grasscutter/game/quest/GameMainQuest.java

@@ -346,6 +346,10 @@ public class GameMainQuest {
     public void save() {
         DatabaseHelper.saveQuest(this);
     }
+    
+    public void delete() {
+        DatabaseHelper.deleteQuest(this);
+    }
 
     public ParentQuest toProto() {
         ParentQuest.Builder proto = ParentQuest.newBuilder()