Compensate level-up points when gaining Hero Status beyond level 220

[halflumi]

Closes #394

[sven-n]

Thanks for your PR, but I think it could be improved, so it doesn't depend on magic values (level 220, 1 as reward) and is more tolerant to changes to the quest data:

            case QuestRewardType.Attribute:
                var attribute = player.SelectedCharacter!.Attributes.FirstOrDefault(a => a.Definition == reward.AttributeReward);
                if (attribute is null)
                {
                    attribute = player.PersistenceContext.CreateNew<StatAttribute>(reward.AttributeReward, 0);
                    player.SelectedCharacter.Attributes.Add(attribute);
                }

                attribute.Value += reward.Value;

                // Compensate level-up points when doing a quest at a later level.
                if (attribute.Definition == Stats.PointsPerLevelUp)
                {
                    var playerLevel = (int)player.Attributes![Stats.Level];
                    player.SelectedCharacter.LevelUpPoints += (playerLevel - quest.MinimumCharacterLevel) * reward.Value;
                }

                await player.InvokeViewPlugInAsync<ILegacyQuestRewardPlugIn>(p => p.ShowAsync(player, QuestRewardType.Attribute, reward.Value, attribute.Definition)).ConfigureAwait(false);
                break;

What do you think?

[halflumi]

That's a good idea! I've adopted your code to the PR.