Migrate validate-signatures cmd to SignatureV2

[aaronc]

ref: #6213

This migrates the x/auth validate-signatures command to use SignatureV2.

---

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• Wrote unit and integration tests
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• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
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[codecov]

Codecov Report

Merging #6470 into master will decrease coverage by 3.54%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #6470      +/-   ##
==========================================
- Coverage   57.53%   53.98%   -3.55%     
==========================================
  Files         501      335     -166     
  Lines       30023    18817   -11206     
==========================================
- Hits        17274    10159    -7115     
+ Misses      11504     7983    -3521     
+ Partials     1245      675     -570     

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[aaronc]

bump

[aaronc]

Should I mark this R4R @sahith-narahari or wait for #6573 ?

[sahith-narahari]

Should I mark this R4R @sahith-narahari or wait for #6573 ?

I would wait for 6573, and add any necessary tests as this is a small PR

[amaury1093]

lgtm, though I agree with @sahith-narahari's remark to use VerifySignature

[aaronc]

lgtm, though I agree with @sahith-narahari's remark to use VerifySignature

if it works go for it!

[sahith-narahari]

Closing this as it's being tackled in #6717