Custom callback router loader

[sergiodxa]

Right now the authLoader used in the callback route owns the whole loader, what happens if I want to do something else there? Example instead of doing:

export const loader = authLoader({ returnPathname: '/dashboard' });

I may want to know who the user is to change returnPathname. The only way I can think right now to let me customize it would be to wrap authLoader in another loader and parse the response, but since I don't have access to the session storage (see #2) I can't access the user data from there.