Log timestamps in RFC3339Milli

[alextes]

📝 Summary

• Changes the timestamp format to human-readable RFC3339.
• Increases the precision to nanosecond from second.

⛱ Motivation and Context

Current log precision is on the second level. On a high volume relay bids are in the hundreds per second, meaning logs, in the thousands, will share the same timestamp and lose their ordering. This would return ordering, and as a bonus make timestamps human-readable.

📚 References

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✅ I have run these commands

• make lint
• make test-race
• go mod tidy
• I have seen and agree to CONTRIBUTING.md

[codecov-commenter]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (c52858a) 33.26% compared to head (6523b33) 33.35%.
Report is 10 commits behind head on main.

Files	Patch %	Lines
common/logging.go	0.00%	5 Missing ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #537      +/-   ##
==========================================
+ Coverage   33.26%   33.35%   +0.09%     
==========================================
  Files          24       24              
  Lines        5090     5315     +225     
==========================================
+ Hits         1693     1773      +80     
- Misses       3178     3318     +140     
- Partials      219      224       +5     

Flag	Coverage Δ
unittests	33.35% <0.00%> (+0.09%)	⬆️

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[JustinDrake]

Side note: this was discussed at the end of MEV Boost call 6.

[metachris]

In mev-boost we're using this with millisecond precision: https://github.com/flashbots/mev-boost/blob/develop-deneb/cli/main.go#L223-L234 + https://github.com/flashbots/mev-boost/blob/develop-deneb/config/vars.go#L14

Any reason for nanoseconds over millis?

[metachris]

(sorry accidentally clicked on close)

[metachris]

@alextes do you want to rebase and update / engage in the comments?

[alextes]

i just didn't see any RFC3339Milli in time and thought it'd be nice to use a standard format. otherwise i'd have gone with that probably.
options are: https://pkg.go.dev/time#pkg-constants

[alextes]

i see now i completely read over your suggestion to use a custom RFC3339Milli format like done in mev-boost if we don't care about nano precision 🙈 .

great suggestion, updated the PR.