fix: avoid native tag as component

[jaw52]

Description

<script setup lang="ts">
let p = "not ok";
</script>

<template>
  <p>{{ p }}</p>
</template>

variable p will be misinterpreted as a component （Component names in vue avoid using html tag）

Linked Issues

This closes https://github.com/antfu/unplugin-vue2-script-setup/issues/133 ,closes https://github.com/antfu/unplugin-vue2-script-setup/issues/135

Additional context

[xiaoxiangmoe]

How about

<script setup lang="ts">
import button from './button.vue'
</script>

<template>
  <button>{{ button }}</button>
</template>

[jaw52]

How about

<script setup lang="ts">
import button from './button.vue'
</script>

<template>
  <button>{{ button }}</button>
</template>

This is the effect of the official scaffolding ofvite + vue3 demo： https://stackblitz.com/edit/vitejs-vite-beh2mo?file=src%2FApp.vue

And. This is the effect of running after this commit

[jaw52]

Do we need to add more test cases？

[xiaoxiangmoe]

Yes, we need more test case.

Include

import button from './button.vue'
import Button from './button.vue'

[jaw52]

Is there any work to be done about this PR @xiaoxiangmoe

[jaw52]

@xiaoxiangmoe I'm ready to review, bro ^_^