Request to merge v-scope into standard Vue 2/3

[caikan]

I like v-scope in petite-vue. It helps me write less boilerplate code for declaring local variables. Before that, I tried to achieve a similar effect with scoped slot or v-for. If this feature is built into the standard Vue, it will bring a lot of convenience.

Demo with scoped slot

https://codesandbox.io/s/use-state-228br?file=/src/App.vue

Demo with v-if

<div v-for="(obj, i) in [data.some.deep.prop]" :key="i">
  <div>{{obj.foo}}</div>
  <div>{{obj.bar}}</div>
  <div>{{obj.baz}}</div>
</div>

[posva]

Duplicate of #505