feat: Update PulpUI to React 19

Summary

React 19 released on 25 April 2024, bringing a fleet of new features to the framework, whilst also deprecated a variety of functions. As PulpUI has already been upgraded to React@18.3.1, this allows the deprecated functions to be make visible for refactor. With the JavaScript eco-system rapidly changing and the introduction of PatternFly 6, migrating to the latest React version will provide a range of performance & security benefits, avoiding future issues when support drops for React 18.

Tasks

1. Understand current dependency requirements for React and peer dependencies.
2. Update Package Files: Bump react, react-dom, @types/react and @types/react-dom to 19.2.8
3. Deploy react/19/migration-recipe codemod to convert deprecated functions to new standards.
4. Deploy types-react-codemod to convert deprecated types to new standards.
5. Run Cypress tests & run UI build steps
6. Document minor issues found for future attention within Github Issues.

Packages to be updated

1. react-markdown

Packages of concern

1. file-saver
2. compare-versions

Found Blockers (To be updated throughout work)

1. @patternfly packages require upgrade to 6.6.0 to support React 19.

References

1. https://react.dev/blog/2024/04/25/react-19-upgrade-guide
2. https://github.com/pulp/pulp-ui/pull/178
3. https://www.npmjs.com/package/react
4. https://www.npmjs.com/package/react-dom
5. https://www.npmjs.com/package/@types/react
6. https://www.npmjs.com/package/@types/react-dom

Start by reviewing the current React and peer-dependency requirements in the package files, then read the React 19 upgrade guide and inspect the referenced migration codemods. Check the PatternFly 6.6.0 blocker and the packages of concern before running the codemods. Done means dependencies and types are updated, Cypress and UI build steps pass, and minor issues are documented in GitHub Issues.