Add version information to the return value of createapp

[tolking]

What problem does this feature solve?

Provide version for PlugIn like V2, Better handling of compatibility

import { createApp } from 'vue'

const app = createApp(App)
console.log(app.version) // undefined

app
  .use(PlugIn)
  .mount('#app')

What does the proposed API look like?

const app = createApp(App)
console.log(app.version) // '3.0.0-beta.15'