support scss file and <style lang="scss" scoped>

[jeryqwq]

the package vue-compile-sfc does not support async function, in brower sass.js doesnt support sync, the fix demo is in my fork branch(https://github.com/jeryqwq/vue3-sfc-loader/blob/main/test/demo.html), or wait for vue3 update(https://github.com/vuejs/vue-next/issues/5231)

 sass: { async  render(args){
        const { data, file, filename, outFile, sourceMap } = args
          return new Promise((reslove, reject) => {
            sass.compile(data, function(result) {
              reslove({
                css: result.text,
                stats: {}
              })
            });
          })
        } }