This is a rather simple hook that allows a plugin to take control over
HTLCs that were accepted, but weren't resolved as part of an invoice
or forwarded to the next hop yet.
The goal is to allow plugins to terminate a route early, perform
intermediate checks before the payment is accepted (check inventory or
service delivery before accepting in order to avoid a refund for
example) or handle an onion differently if it has a different
realm (cross-chain atomic swaps).
This doesn't implement serializing the payload or deserializing it,
instead just passes the full context along. The details for
serializing and deserializing will be implemented in a future commit.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
7499f7ddd4