Add code to run SonarScanner on test unit runs

[clintoncwolfe]

Description

Modifies verify.sh to download sonarscanner and run it on test unit runs where the CI_ENABLE_COVERAGE flag is set. This will also upload the coverage/coverage.json file to sonarcloud.

Issues Resolved

List any existing issues this PR resolves, or any Discourse or StackOverflow discussion that's relevant

Check List

• [ ] New functionality includes tests
• [ ] All tests pass
• [ ] rake lint passes
• [ ] All commits have been signed-off for the Developer Certificate of Origin. See https://github.com/chef/chef/blob/master/CONTRIBUTING.md#developer-certification-of-origin-dco

[clintoncwolfe]

Merging just so the pipeline will be created.