FED-3114: Lazy

[kealjones-wk]

Depends on https://github.com/Workiva/react-dart/pull/406

Motivation

We need React.lazy in order to support some new asynchronous component patterns.

Changes

• Add React.lazy
• Add a lot of test coverage

Release Notes

Review

See CONTRIBUTING.md for more details on review types (+1 / QA +1 / +10) and code review process.

Please review:

QA Checklist

• [ ] Tests were updated and provide good coverage of the changeset and other affected code
• [ ] Manual testing was performed if needed
  • [ ] Steps from PR author:
    • [ ] Run the suspense example and ensure it is working correctly still
    • [ ] CI Passes
  • [ ] Anything falling under manual testing criteria outlined in CONTRIBUTING.md

Merge Checklist

While we perform many automated checks before auto-merging, some manual checks are needed:

• [ ] A Frontend Frameworks Design member has reviewed these changes
• [ ] There are no unaddressed comments - this check can be automated if reviewers use the "Request Changes" feature
• [ ] For release PRs - Version metadata in Rosie comment is correct