perf: Speedup cachekv iterator on large deletions & IBC v2 upgrade logic (backport #10741)

[mergify]

This is an automatic backport of pull request #10741 done by Mergify.
Cherry-pick of 314e1d5 has failed:

On branch mergify/bp/release/v0.42.x/pr-10741
Your branch is up to date with 'origin/release/v0.42.x'.

You are currently cherry-picking commit 314e1d52c.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   store/cachekv/memiterator.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   CHANGELOG.md
	both modified:   store/cachekv/store_bench_test.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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[codecov]

Codecov Report

Merging #10746 (12dc5fa) into release/v0.42.x (01fac64) will not change coverage.
The diff coverage is 100.00%.

@@               Coverage Diff                @@
##           release/v0.42.x   #10746   +/-   ##
================================================
  Coverage            62.96%   62.96%           
================================================
  Files                  622      622           
  Lines                41343    41343           
================================================
  Hits                 26033    26033           
  Misses               12916    12916           
  Partials              2394     2394           

Impacted Files	Coverage Δ
store/cachekv/memiterator.go	80.00% <100.00%> (ø)