[CLIENT-8013] Implement `VideoInputTest`.

[mhuynh5757]

Contributing to Twilio

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• [x] I acknowledge that all my contributions will be made under the project's license.

Pull Request Details

JIRA link(s):

• CLIENT-8013

Description

This PR implements the first version of the VideoInputTest as described the IDL in the JIRA link.

Burndown

Before review

• [x] Updated CHANGELOG.md if necessary
• [x] Added unit tests if necessary
• [x] Updated affected documentation
• [x] Verified locally with npm test
• [x] Manually sanity tested running locally
• [x] Included screenshot as PR comment (if needed)
• [x] Ready for review

Before merge

• [ ] Got one or more +1s
• [ ] Re-tested if necessary