Cover Block: Add Slideshow-type functionality, options for multiple covers

### Impacted plugin

Jetpack

### What

Enhance the WordPress.com Cover Block by enabling support for multiple cover images with integrated slideshow functionality. This feature would allow users to create dynamic, visually engaging content by cycling through several cover images and call-to-action within a single block.

### How

This request originated from a suggestion sent by user on interaction 8447400-zd-a8c.

They initially suggested that the Slideshow Block be adapted to include more options to add links and buttons, as shown on the example shared (https://www.josephprince.com/).

While understanding the purpose of the Slideshow Block, I think it might be best to explore how we can update the Cover Block to support multiple rotating covers, with each Cover containing their own blocks. Some standard slideshow management options can be added like transition type and transition delays.

Start by comparing the WordPress.com Cover Block with the Slideshow Block, the two entry points named in the issue. The request is for multiple rotating covers, each containing its own blocks, with options such as transition type and delay; the issue does not name files or tests.

Written by the indexing model from the issue text.