public StyleData findStyle(Class clazz, String styleName) {
        var styles = getClassStyleMap().get(clazz);
        for (var style : styles) {
            if (style.name.equals(styleName)) {
                return style;
            }
        }
        return null;
    }
Creates a new StyleData object if one with the same name currently does not exist. If it does exist
it is returned and the properties are wiped. ClassName and deletable flag is retained.
@param className
@param styleName
@return
core/src/com/ray3k/skincomposer/data/JsonData.java