[feature request] use `vue-typescript` as drop-in replacement of `typescript`

Today to use Typescript TypeChecker API on SFC files, or other internal TS APIs, we have to extract the script content using @vue/compiler-sfc before using them. Doing this transform prevents us to keep the original context.

The idea would be to use the vue-typescript package as a drop-in replacement for typescript package.

Example:

import * as ts from 'vue-typescript'

const program = ts.createProgram([`my-component.vue`], {}) // <- vue-typescript would allow to load .vue sfc files
const checker = program.getTypeChecker(); // this would be available!

[johnsoncodehk]

We can’t abstract type checker api into vue-typescript, because one vue document is correspond to multiple TS source file, but I make a example to show how to use @volar/vue-language-core api to do it, see https://github.com/johnsoncodehk/volar-starter/blob/example-extra-prop-type/see-hello-world-props.js.

[johnsoncodehk]

@sxzz The output error is because getDefaultLibFileName result incorrect, fixed by https://github.com/johnsoncodehk/volar-starter/commit/365b0367d5ac2533ef3ea062f866e6703f09ce30.