[Feature Request]: v2 redefine spa and mpa config

[ErKeLost]

What problem does this feature solve?

new config

  compilation: {
    input: {
      index_a: './index_a.html',
      index_b: './index_b.html',
    },
  }

Add apptype attribute to configure spa, mpa or custom

The only difference between spa and mpa in type lies in the//path resolution problem when htmlfallback

Really configure compilation directly as long as it is mpa: {input:{}}

If custom is set, the processing mechanism of html in the server will not be processed in middleware mode

What does the proposed API look like?

none