React 18 Update

[RayRedGoose]

In our v8 Canvas Kit release this fall we will be upgrading to React 18. React 18 introduced several new features, but the most impactful change is the new concurrent render API. In the new API, you'll use the .createRoot() method which replaces .render(), which adds all of the improvements of React 18 and allows you to use concurrent features. Without it React behaves the same as it did in version 17.

Canvas Kit doesn’t use the render API directly in our packages. But Storybook uses it to render Canvas Kit components. So we needed to have Storybook dependencies supporting React 18 as well.

Results of update:

Upgrades of react, react-dom, @types/react and @types/react-dom were made in this PR

Upgrade of Storybook was made in this PR

• Storybook 6.5 uses a new root method by default, but using the legacy root method did not break Storybook building or any component functionality, React 18 features just ignored.

Conclusion:

Impact on CK:
Updating to React 18 doesn't require to change a lot in our code (only switch to new types). To see v18 features in action it requires updating Storybook to v6.5+ supporting React 18.

Impact on users:
This change will not impact users who are already on v7 and are looking to upgrade to v8 as v8 will support the same React versions as v7 (React 16.14 and 17.X) while still giving them the ability to upgrade to React 18 as needed. Although we didn't use any new features from React 18 in v8, future updates to Canvas Kit may require upgrading to React 18 to support them.