fix: use jsx classic runtime to avoid issues on react < 18

[cjbell]

When using React < 18 users will run into this error:

Module not found: Error: Can't resolve 'react/jsx-runtime' in '[FILE]'
Did you mean 'jsx-runtime.js'?
BREAKING CHANGE: The request 'react/jsx-runtime' failed to resolve only because it was resolved as fully specified
(probably because the origin is strict EcmaScript Module, e. g. a module with javascript mimetype, a '*.mjs' file, or a '*.js' file where the package.json contains '"type": "module"').
The extension in the request is mandatory for it to be fully specified.
Add the extension to the request.

The issue is described in this thread: facebook/react#20235

The fix was implemented in React 18, but the only "fixes" that exist if we're using the JSX runtime are to patch webpack configs, which is not great.

Instead, this PR implements an option to use the "classic" JSX runtime, which is the createElement API as a workaround so that react/jsx-runtime is never referenced. To do so, we also needed to ensure that import React from "react" was at the top of all of our JSX components, which is what the babel-plugin-require-react does.

I tested this locally in our example apps with a build and everything works

[changeset-bot]

🦋 Changeset detected

Latest commit: 7f21868

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 5 packages

Name	Type
@knocklabs/react-core	Patch
@knocklabs/react	Patch
@knocklabs/react-native	Patch
nextjs-example	Patch
@knocklabs/react-native-example	Patch

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[connorlindsey]

Looks good! Will need a changeset as well

[kylemcd]

Looks good! Might want to check to see if this has any effect on the bundle size before publishing.