chore: add validation for MsgAcknowledgement.

[DimitrisJim]

Description

part of #7466

(some random changes brought in due to linter)

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• [ ] Targeted PR against the 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 and Go style guide.
• [ ] Wrote unit and integration tests.
• [ ] Updated relevant documentation (docs/).
• [ ] Added relevant godoc comments.
• [ ] Provide a conventional commit message to follow the repository standards.
• [ ] Include a descriptive changelog entry when appropriate. This may be left to the discretion of the PR reviewers. (e.g. chores should be omitted from changelog)
• [ ] Re-reviewed Files changed in the GitHub PR explorer.
• [ ] Review SonarCloud Report in the comment section below once CI passes.

[sonarcloud[bot]]

Quality Gate passed for 'ibc-go'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud