Feature Request: Slideshow Block, More Customization Controls

### Impacted plugin

Jetpack

### What

Add more contols to the block, so it's more customizable - like toggle captions, change captions style, toggle pagination..

### How

There are many UI elements visible on the slider, but none can be customized.

Some controls that can be added to the quick action or the sidebar:

**Pagination:**
- Toggle - on, off, on hover..
- Alignment / Position (left right center, top right corner...)
- Style (points, lines, numbers... )

**Captions:**
- Toggle - on, off, on hover..
- Style - Background color, text color, text style..
- Position

**Arrows:**
- Toggle
- Style

Start by locating Jetpack's Slideshow Block and reviewing its existing visible UI elements. Compare the current pagination, captions, and arrows with the requested customization areas, then confirm the intended controls and styling before implementation; done means the agreed options are available and work in the block.

Written by the indexing model from the issue text.