This adds a test to the commit sweeper resolver to ensure it behaves
properly if the local node breaches a channel.
In this situation the remote party is expected to sweep the breached
output to itself and therefore the local party won't be able to recover
any funds.
Sweeping anchors and being able to bump the fee was already added in a
previous commit. This commit extends anchor sweeping with an anchor
resolver object that becomes active after the commitment tx confirms.
At that point, the anchors do not serve the purpose of getting the
commitment tranaction confirmed anymore. It is however still possible to
reclaim some of their value if using a low fee rate.
We use the fact that we can tell whether the commit is local or remote
by inspecting the witness script. We cannot use the maturity delay
anymore, as we can have delayed to_remote outputs also now.
Co-authored-by: Joost Jager <joost.jager@gmail.com>
