Carousel view

A horizontally scrolling view with previous/next navigation controls.

```obs-gallery
sources:
  - type: local
    path: Images/Screenshots
view:
  type: carousel
```

Move between slides with the arrow buttons, the dots under the slides, the ← / → keys (with the carousel focused), or by swiping on a touch screen. Click a slide to open it in the image viewer.

The carousel always holds every image, so the pagination and itemsPerPage view options don't apply to it.