Focus - Carousel Arrows

[katknow]

When tabbing through the carousel in the Focus test for Accessibility Insights for Web, when there is a carousel on the page the arrows to navigate to the next slide are getting pinged for not having enough visual difference when tabbed to.

[kimisgold]

Focusable elements should now all be using a 1px red border. I did notice that item carousel has its own focus styles for individual slide buttons, but if they're a problem, I would identify that as an issue specific to the module. Otherwise, this is ready for testing.

[katknow]

If Carousel is it's own thing then this should be good to go in terms of theme, everything else has the border, it's just the arrows and dots.