Add support for claiming validator commission

[george-aj]

Proposed changes

Adds client functionality to be able to claim validator commissions.

Issues

Links to any issues resolved.

Types of changes

What types of changes does your code introduce? Put an x in the boxes that apply

• [ ] Bugfix (non-breaking change that fixes an issue)
• [x] New feature (non-breaking change that adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to stop working as expected)
• [ ] Something else (e.g. tests, scripts, example, deployment, infrastructure, ...)

Checklist

Put an x in the boxes that apply.

• [x] I have read the CONTRIBUTING document.
• [x] I have based my branch, and I am making a pull request against, the main branch.
• [x] Checks and tests pass locally.

If applicable

• [ ] I have added tests that prove my fix is effective or that my feature works.
• [x] I have checked that code coverage does not decrease.
• [x] I have added/updated the documentations.

Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did, what alternatives you considered, etc.