This commit corrects a bug in TxWeightEstimator that could result in
underestimations for transactions involving NestedP2WPKH and NestedP2WSH
inputs. The scriptSig data push is now accounted for in a proper size
constant, and the input count is now incremented in both. This would
only be detectable in the event that the number of non-nested inputs and
the total number of inputs straddle the discontinuities in the
CompactSize encoding, e.g. 253, 2^16-1, or 2^32-1.
In this commit, we update the `CommitSpendNoDelay` method to be aware of
the alternate spending mechanism for commitments that don't have a tweak
for the remote party's non-delay output. We also add a new witness type
so callers can convey their expected signing path.
This commit is a step to split the lnwallet package. It puts the Input
interface and implementations in a separate package along with all their
dependencies from lnwallet.
