refs https://github.com/TryGhost/Product/issues/3832
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### <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.
