When paying with injectpaymentonion we need to manually decode the error
from the onion.
Changelog-None.
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
Routes contain only routing information and the payment they're linked
to can be obtained through the payment_hash. We remove the dependency of
route building routines from the payment itself. In order to make
plain payment information available we define a payment_info structure.
