To make it possible to use a remote lnrpc server as a signer for our
wallet, we need to change our main interface to sign the message instead
of the message's digest. Otherwise we'd need to alter the
lnrpc.SignMessage RPC to accept a digest instead of only the message
which has security implications.
The FundingPsbtFinalize step is a safety measure that assures the final
signed funding transaction has the same TXID as was registered during
the funding flow and was used for the commitment transactions.
This step is cumbersome to use if the whole funding process is completed
external to lnd. We allow the finalize step to be skipped for such
cases. The API user/script will need to make sure things are verified
(and possibly cleaned up) properly.
With the middleware handler in place, we now need to add a new gRPC
interceptor to the interceptor chain that will send messages to the
registered middlewares for each event that could be of interest to them.
The RPC DeletePayment allows deleteing single payment from its ID. When calling with `FailedHtlcsOnly` set in the request only failed HTLCs of this payment will be deleted.
This field will be examined later down the stack along with the set of
feature bits to determine if explicit channel commitment type
negotiation is possible or not.
To avoid a naming conflict with etcd, we rename our very generic
rpc.proto to lightning.proto to match the service name that's declared
within. This will break many external tutorials and possibly also our
API docs but the change needs to be done eventually.
