[Backport] PATCH /setup fails when converting OAuth to SSO because default values are not applied like POST

[Backport] [UI] User is shown connected in webUI after converting exisiting OAuth to SSO via setup endpoint

[backport][UI] No encryption warning for group folder when the server-side encryption is enabled

[Backport] check-admin-config returns incorrect config status after integration 0Auth re-setup with project folder until admin settings page is loaded

[backport][UI] Project folder form header is in disabled mode even when the form fields are visible

[backport] Improve validation error messages for integration setup API

[backport] Show project-based semantic identifiers on work package links in Nextcloud

[backport] Do not revoke access tokens and let OpenProject handle the revocation