vcmi: remove MAXED_SPELL

Replace it by SPELL bonus with val = 3

lib/CHeroHandler.cpp

@@ -615,9 +615,10 @@ std::vector<std::shared_ptr<Bonus>> SpecialtyInfoToBonuses(const SSpecialtyInfo
 			break;
 		}
 	case 7: //maxed mastery for spell
-		bonus->type = Bonus::SPECIAL_FIXED_VALUE_ENCHANT;
+		bonus->type = Bonus::SPELL;
 		bonus->subtype = spec.subtype; //spell id
-		bonus->val = 3; //to match MAXED_BONUS
+		bonus->val = 3; //to match MAXED_SPELL
+		bonus->valType = Bonus::INDEPENDENT_MAX;
 		result.push_back(bonus);
 		break;
 	case 8: //peculiar spells - enchantments

lib/HeroBonus.cpp

@@ -1649,7 +1649,7 @@ JsonNode subtypeToJson(Bonus::BonusType type, int subtype)
 		return JsonUtils::stringNode(CSkillHandler::encodeSkillWithType(subtype));
 	case Bonus::SPECIAL_SPELL_LEV:
 	case Bonus::SPECIFIC_SPELL_DAMAGE:
-	case Bonus::MAXED_SPELL:
+	case Bonus::SPELL:
 	case Bonus::SPECIAL_PECULIAR_ENCHANT:
 	case Bonus::SPECIAL_ADD_VALUE_ENCHANT:
 	case Bonus::SPECIAL_FIXED_VALUE_ENCHANT:
@@ -1756,7 +1756,7 @@ std::string Bonus::nameForBonus() const
 		return CSkillHandler::encodeSkill(subtype);
 	case Bonus::SPECIAL_SPELL_LEV:
 	case Bonus::SPECIFIC_SPELL_DAMAGE:
-	case Bonus::MAXED_SPELL:
+	case Bonus::SPELL:
 	case Bonus::SPECIAL_PECULIAR_ENCHANT:
 	case Bonus::SPECIAL_ADD_VALUE_ENCHANT:
 	case Bonus::SPECIAL_FIXED_VALUE_ENCHANT:

lib/HeroBonus.h

@@ -287,7 +287,6 @@ public:
 	BONUS_NAME(SPECIAL_SPELL_LEV) /*subtype = id, val = value per level in percent*/\
 	BONUS_NAME(SPELL_DAMAGE) /*val = value*/\
 	BONUS_NAME(SPECIFIC_SPELL_DAMAGE) /*subtype = id of spell, val = value*/\
-	BONUS_NAME(MAXED_SPELL) /*val = id. deprecated in favour of SPECIAL_FIXED_VALUE_ENCHANT*/\
 	BONUS_NAME(SPECIAL_PECULIAR_ENCHANT) /*blesses and curses with id = val dependent on unit's level, subtype = 0 or 1 for Coronius*/\
 	BONUS_NAME(SPECIAL_UPGRADE) /*subtype = base, additionalInfo = target */\
 	BONUS_NAME(DRAGON_NATURE) \