[Feature] make harmony-vchart easy to use

[neuqzxy]

What problem does this feature solve?

鸿蒙内定义spec太麻烦了，spec内有各种类型包括函数，还有嵌套类型。 目前的spec定义的interface没法用，在Harmony中会报错。

What does the proposed API look like?

harmony内可用的spec定义描述 或者命令形式的API