LSPS5 -> more follow ups

[martinsaposnic]

Addressing comments #3662 (comment), #3662 (comment) and lightning/blips#55 (comment)

Changes:

• lightning-liquidity README is updated
• We stop logging at the Error / Info level when the client / manager is dealing with unknown peers, unknown request IDs, missing handlers, etc

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[tnull]

LGTM

I think at some point we need to more fundamentally rethink our logging scheme (e.g., not sure if we should start logging at ERROR for some of the more unlikely/severe cases). but this is a clear improvement for now.

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[codecov]

Codecov Report

❌ Patch coverage is 22.22222% with 14 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.93%. Comparing base (bb48bbc) to head (7782e3d).
⚠️ Report is 12 commits behind head on main.

Files with missing lines	Patch %	Lines
lightning-liquidity/src/manager.rs	0.00%	7 Missing ⚠️
lightning-liquidity/src/lsps2/client.rs	25.00%	6 Missing ⚠️
lightning-liquidity/src/lsps5/client.rs	66.66%	1 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@## main #3972 +/- ##
==========================================
- Coverage 88.93% 88.93% -0.01% 
==========================================
Files 174 174 Lines 123875 123880 +5 Branches 123875 123880 +5 ==========================================
+ Hits 110169 110171 +2 - Misses 11253 11259 +6 + Partials 2453 2450 -3 

Flag	Coverage Δ
fuzzing	22.62% <0.00%> (+0.44%)	⬆️
tests	88.76% <22.22%> (-0.01%)	⬇️

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