⭐️New: Add vue/no-deprecated-slot-scope-attribute rule

[ota-meshi]

vue/no-deprecated-slot-scope-attribute rule reports deprecated slot-scope attribute in Vue.js v2.6.0+.

<template>
  <ListComponent>
    <!-- ✓ GOOD -->
    <template v-slot="props">
      {{ props.title }}
    </template>
  </ListComponent>
  <ListComponent>
    <!-- ✗ BAD -->
    <template slot-scope="props">
      {{ props.title }}
    </template>
  </ListComponent>
</template>

---

refs #800 (comment)

[lianghx-319]

I need this rule too. Because I dont want my team use old slot in vue 2.6.x version.

[sybrendotinga]

@ota-meshi any updates on this? We would love to use this great improvement!