Include payment hash in more early payment logs

Include payment hash in more early payment logs

If a user has issues with a payment, the most obvious thing they'll
do is check logs for the payment hash. Thus, we should ensure our
logs that show a payment's lifecycle include the payment hash and
are emitted (a) as soon as LDK learns of the payment, (b) once the
payment goes out to the peer (which is already reasonably covered
in the commitment transaction building logs) and (c) when the
payment ultimately is fulfilled or fails.

Here we improve our logs for both (a) and (c).