Add keyboard option to carousel

[hnrch02]

Also adds unit tests for keyboard events.

Fixes #14468.

[hnrch02]

@cvrebert Docs wording LGTY?

[cvrebert]

👍

[hnrch02]

/to @fat

[fat]

I like to think of the plugins like an ecosystem – and if we add this option in one place, we should add it to all the plugins…

That said, I'm not really crazy about adding this keyboard option. Seems like a bit of a weird use case – and something that could be solved in other ways.

[fat]

If i'm missing some other perspective though, let me know :) - the code looks really good, and swooned at the unit tests

[hnrch02]

I agree that the specific use case mentioned in #14468 is weird but I feel that this is a small change that helps out somebody which is entirely relying on the data-api. Besides that we have a keyboard option for modals, removing the escape listener for modals would be just as easy as the workarounds you suggested in #14468.

[fat]

oh yeah… hrm… it does still really feel wrong to have an option that is essentially fuck accessibility, but your call.

can't remember the exat details of the modal keyboard option, but i think i was also not super excited about it

[fat]

merged it… i think we should audit in 4 and see if we can't have a more graceful way of turning these types of things off across plugins tho