Enable to customize the authorizer for router

[git-hulk]

Component(s)

router

Is your feature request related to a problem? Please describe.

In some cases, we would like to customize the message when the authorization error occurs.

Describe the solution you'd like

To achieve this goal, we need those potential changes:

• Change Authorizer to an interface in HandlerOptions
• Allow to pass the Authorizer via router's config and BuildGraphMuxOptions

Describe alternatives you've considered

We're already a wundergraph Enterprise customer. And happy to submit a PR to resolve this if it sounds good to you.

Additional context

No response