This, in the case of data loss on a channel with `option_static_remotekey`
negotiated, allows to likely (if the dbid is not unreasonable) recover
the funds from a remote unilateral close just with the hsm_secret.
Changelog-added: A new command, 'guesstoremote', is added to the hsmtool. It is meant to be used to recover funds after an unilateral close of a channel with `option_static_remotekey` enabled.
This takes a dbid, a "depth" (how many points to dump), the hsm_secret
path, and a potential password to dump informations about all
commitments until the depth.
Co-Authored-By: Sjors Provoost <sjors@sprovoost.nl>