feat: add ValidateDenom for MsgSend, MsgRetire, and MsgCancel

[aleem1314]

Description

Closes: #551

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Author Checklist

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please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

[codecov]

Codecov Report

Merging #554 (5dc114c) into master (f7c2cb8) will decrease coverage by 0.11%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #554      +/-   ##
==========================================
- Coverage   76.06%   75.94%   -0.12%     
==========================================
  Files         105      105              
  Lines       13831    13829       -2     
==========================================
- Hits        10520    10502      -18     
- Misses       2699     2709      +10     
- Partials      612      618       +6     

Flag	Coverage Δ
experimental-codecov	75.94% <100.00%> (-0.12%)	⬇️
stable-codecov	67.30% <100.00%> (-0.14%)	⬇️

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[ryanchristo]

tACK