Replace get_route with get_route_and_payment_hash

Replace get_route with get_route_and_payment_hash

The interface for get_route will change to take a scorer. Using
get_route_and_payment_hash whenever possible allows for keeping the
scorer inside get_route_and_payment_hash rather than at every call site.

Replace get_route with get_route_and_payment_hash wherever possible.
Additionally, update get_route_and_payment_hash to use the known invoice
features and the sending node's logger.