fix: handle cors issue

[Julien-R44]

Resolve #13

This PR results in a breaking change: the Vite middleware must be added by the user in his own kernel.ts file like this :

// file: kernel.ts

// ...
server.use([
  // ...
  () => import('@adonisjs/cors/cors_middleware'),
  () => import('@adonisjs/vite/vite_middleware'),
])

Of course, the Vite middleware must be defined AFTER the cors one.

I needed to make this change, as otherwise the Vite middleware was constantly executed BEFORE the adonisjs/cors middleware, and therefore I had no way of retrieving the cors headers to inject.