fix: enforce name casing for unregistered components

[vaibhav11s]

fix #288
added optional param for vue/component-name-in-template-casing

Description

vue/component-name-in-template-casing doesn't work when the component is global or auto-imported (like in nuxt).

Linked Issues

#288

Additional context

[qin-guan]

Hey! Upgraded to the latest version with this change and found that it breaks camel case components which are imported within SFC itself, even though it is valid SFC syntax. For example, using framework7-vue where component names are prefixed with f7:

<script setup lang="ts">
	import { f7Button } from 'framework7-vue'
</script>

<template>
	<f7Button>Hello</f7Button>
</template>

It will get fixed to

<script setup lang="ts">
</script>

<template>
	<F7Button>Hello</F7Button>
</template>

Which is invalid. Should this change be reconsidered?

[antfu]

In that case, I think we better revert it and find a better solution later. @qin-guan do you want to send a PR?