refs https://github.com/TryGhost/Product/issues/3832
---
<!-- Leave the line below if you'd like GitHub Copilot to generate a
summary from your commit -->
<!--
copilot:summary
-->
### <samp>🤖 Generated by Copilot at 7eda74c</samp>
This pull request improves the validation, customization, and feedback
of various form components and modals in the admin-x-settings app. It
also adds new components for user detail modal sections and modifies the
user type to allow null values for social accounts. Additionally, it
adds `dirty` props to some integration modals and a `data-testid`
attribute to the exit settings button. It also deletes an unused file.
refs https://github.com/TryGhost/Product/issues/3729
- Wired up the Pintura Integration to AdminX.
---
<!-- Leave the line below if you'd like GitHub Copilot to generate a
summary from your commit -->
<!--
copilot:summary
-->
### <samp>🤖 Generated by Copilot at 4d33355</samp>
This pull request adds the ability to customize the Pintura image editor
with custom JS and CSS files in the advanced settings modal. It
introduces a new `files.ts` file in the `api` folder, which provides a
hook and a helper function for uploading and retrieving files. It also
modifies the `PinturaModal.tsx` component to use these functions and
display the settings.
