Try to hack collapsing columns, make modal menu scrollable on mobile phones, add remember me button to nextcloud

Allow globally overriding slots in the light dom of components and use it to override the auth-info slot in the Nextcloud file picker

Otherwhise it will try to access it an error out when trying to open
the dialog.

Pull out nextcloudfilepicker styles to file-handling styles, styling, translation and function of clipboard