Upgrade to React 19

## Summary
After https://github.com/mi6/ic-ui-kit/issues/2891 Storybook was upgraded so that we could upgrade to React 19, however there were more packages that needed updating in order for React 19 to work. Some of them hadn't been updated to work with React 19 yet so all other upgrades have been left for this ticket.

## 💬 Description
What needs updating:

- Latest version of [mdx-js/react](https://www.npmjs.com/package/@mdx-js/react?activeTab=versions)
- Cypress v14
- Storybook addon performance (anything greater than 0.17.3) - this is the package that hasn't been updated to React 19 yet, it hasn't had a [new version](https://www.npmjs.com/package/storybook-addon-performance?activeTab=versions) in the last year. It might be that we need to look at an alternative instead.
- [React v19](https://react.dev/blog/2024/04/25/react-19-upgrade-guide)

## 💰 Use value
Allows users to use React 19 with ICDS.

Start by reviewing the package dependencies and the Storybook and Cypress setup against the React 19 upgrade guide. Check the listed mdx-js/react, Cypress, Storybook addon performance, and React versions, then verify that the addon or an alternative works and that the project builds and tests successfully with React 19.

Written by the indexing model from the issue text.