Added 'Gradable' in item DB (#7218)

* Added 'Gradable' in item DB
** The field defines if the item can be graded (renewal). (Default: false)

Thanks to @attackjom, @Lemongrass3110 !

src/tool/yaml2sql.cpp

@@ -626,6 +626,8 @@ static bool item_db_yaml2sql(const std::string &file, const std::string &table)
 			column.append("`equip_level_max`,");
 		if (appendEntry(input["Refineable"], value))
 			column.append("`refineable`,");
+		if (appendEntry(input["Gradable"], value))
+			column.append("`gradable`,");
 		if (appendEntry(input["View"], value))
 			column.append("`view`,");
 		if (appendEntry(input["AliasName"], value, true))