Allow Banner CTA actions to open a specific Update in the in-app Updates widget

I want to be able to configure an Outbound Banner CTA button with an action type like "Open Update" and select an existing Update.

When clicked, this action should trigger the in-app Updates/Changelog popup widget to open that specific Update internally (using the SDK's existing `manually_open_changelog_popup` programmatic behavior), rather than navigating the user away to the public standalone Updates page.

This keeps the user inside the in-app experience.