Carousel enhancement: Add setting to hide image title & caption

### Impacted plugin

Jetpack

### What

Add a user-facing setting to hide the image title and caption, similar to the existing settings for hiding comments and EXIF metadata.

### How

Sometimes users to want the carousel to simply display their images and nothing else.

Currently, there is no easy way to achieve that without a bit of manual work (CSS customization or manually removing all image titles/captions from the media gallery).

This experience could be improved by introducing a setting to hide image titles/captions. We could also lump this in with a setting to hide the "i" button and information panel altogether.


This was previously brought up here:

https://github.com/Automattic/jetpack/issues/15224

But that issue was closed after we added the setting to hide only comments.

Start by locating the Jetpack carousel settings and the existing controls for hiding comments and EXIF metadata. Trace how those settings affect the image information panel, then define the setting's scope and verify that titles and captions are hidden while the carousel continues to display images.

Written by the indexing model from the issue text.