Include payment hash in more early payment logs

[TheBlueMatt]

Based on #2492,

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).

As a nice bonus, we also remove a sha256 hash of a payment preimage in every forwarded HTLC claim :).

[codecov-commenter]

Codecov Report

❌ Patch coverage is 85.71429% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.52%. Comparing base (0c25046) to head (5a1f212).
⚠️ Report is 5517 commits behind head on main.

Files with missing lines	Patch %	Lines
lightning/src/ln/outbound_payment.rs	77.77%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2515      +/-   ##
==========================================
- Coverage   90.53%   90.52%   -0.01%     
==========================================
  Files         107      107              
  Lines       56923    56931       +8     
  Branches    56923    56931       +8     
==========================================
+ Hits        51533    51537       +4     
- Misses       5390     5394       +4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.