Encode routed resources in the Conn type

[owickstrom]

As described in https://owickstrom.github.io/hyper/#resource-routers, routed resources are not part of the Conn type. They should be encoded as a component in the Conn, if possible. My hope is that a resource A referencing another resource B, can do so through the conn, making dependencies explicit:

\conn -> html (linkTo conn.components.routes.home (text "Home Page") conn)

I think this would also result in less need for explicit type annotations when having mutually referencing resources.

[owickstrom]

Closing this in favor of new router work.