This takes an {payment_id} and {description}.
It looks for all chain + channel events that match
that {payment_id} and updates the description for those events.
We return all the updated events. If no events are updated, an empty
list is returned.
Changelog-Added: PLUGINS: bookkeeper has a new RPC `bkpr-editdescriptionbypaymentid` which will update the description for any event with matching payment_id