ibc: tendermint misbehaviour should use block hash for equality check

[colin-axner]

Description

closes: #7911

---

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• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[cwgoes]

ACK

[cwgoes]

(just to confirm: we don't check this anywhere else?)

[codecov]

Codecov Report

Merging #7928 (39562d5) into master (a8ef4a3) will decrease coverage by 0.00%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##           master    #7928      +/-   ##
==========================================
- Coverage   54.18%   54.17%   -0.01%     
==========================================
  Files         612      612              
  Lines       39000    39000              
==========================================
- Hits        21131    21129       -2     
- Misses      15697    15698       +1     
- Partials     2172     2173       +1     

[colin-axner]

(just to confirm: we don't check this anywhere else?)

good call, I updated ValidCommit to use the block ID hash as well