Adapting mempool for cometbft release

[Ferret-san]

This PR addresses the following comments from @tzdybal on #793

Consider re-importing latest version of mempool from cometbft (as separate, follow-up PR).

This PR reimports the latest version of mempool from cometbft 0.37.0

[codecov]

Codecov Report

Patch coverage: 86.20% and project coverage change: +0.13 🎉

Comparison is base (e40e5a9) 54.01% compared to head (a8b0ff0) 54.14%.

❗ Current head a8b0ff0 differs from pull request most recent head ca05435. Consider uploading reports for the commit ca05435 to get more accurate results

Additional details and impacted files

@@                Coverage Diff                 @@
##           diego/cometbft     #991      +/-   ##
==================================================
+ Coverage           54.01%   54.14%   +0.13%     
==================================================
  Files                  63       54       -9     
  Lines                6680     6076     -604     
==================================================
- Hits                 3608     3290     -318     
+ Misses               2682     2438     -244     
+ Partials              390      348      -42     

Impacted Files	Coverage Δ
mempool/v1/mempool.go	85.47% <86.20%> (+3.10%)	⬆️

... and 15 files with indirect coverage changes

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[gupadhyaya]

lgtm.

[tzdybal]

LGTM. Expected more changes lol.