Pass headers to input option for schema fetching

[CIP43R]

Right now, there's only the option to set the path to an external openAPI specification. However, if the endpoint requires authentication, kubb will throw an error, because it cannot load the schema.

It'd be amazing if we could just add headers to the input option like so:

export default defineConfig({
  name: 'Backend',
  input: {
    path: 'https://something.test.azurewebsites.net/api/openapi.json',
    headers: {
       'X-MS-Auth': 'something'
    }
  },
})

and then the headers will just be used for the initial fetch of the schema

I know it's kind of an edge case, since you'd usually generate the schemas from a local backend, but in my case, we only have access to an already existent API that we don't have access to code-wise.

[stijnvanhulle]

@CIP43R I would suggest calling your swagger with auth before return the config

export default defineConfig(async () => {
const data = axios.get(
'https://something.test.azurewebsites.net/api/openapi.json',  
headers: {
   'X-MS-Auth': 'something'
})


return {
  name: 'Backend',
  input: {
    data
  },
}
})