This commit fixes#8535 by changing how we assess toSelfAmount inside
the chainWatcher.
In certain cases users may wish to close out channel funds to external
delivery addresses set either during open or close.
Prior to this change we only consider addresses that our wallet is
aware of.
This change now identifies outputs as to_self outputs if the delivery
script matches OR if our wallet is aware of the address. In certain
edge cases it can be possible for there to be more than one output
that matches these criteria and in that case we will return the sum
of those values.