(HATCH-478) implement react-ui tests

[snoattoh]

Description

This brings the test coverage for the react-ui package up to 90%. Note, a good amount of the react-ui tests have been smoke tests since the restClient (or dataSource) and the hatchedReact components bring the elements together.

There are still tests that could use more coverage, but I've opted to prioritize other work rather than exceeding a sufficient coverage.

Jira ticket links

https://bitovi.atlassian.net/browse/HATCH-478

Test Plan

1. Navigate to the react-ui directory
2. npm run test:coverage
3. Make sure there are no errors, but also review the code of course, some of the tests could be misguided.

Definition of done

• [x] Does new code have 90% testing coverage (100% for core) of both unit and E2E tests?
• [x] Is code secure? If applicable, add security notes to the description.
• [x] Do all new TODO comments have Jira links with enough information?
• [x] Were all changes published and deployed to the grid?
• [ ] Has the browser error-console been reviewed to not contain new errors introduced by these code changes?
• [x] The site looks “good” above 1000px width.
• [ ] The site looks “good” when the window height is small. No double scrollbars.
• [x] Were the changes tested to ensure 508 compliance?