Move non-draggable implementation of carousel-items images, from js to css

[GeoSot]

With out knowing the exact reason of dragging prevent default, being there, I suppose is more efficient to handle it using some simple css to achive the same result

Could also be pointer-events: none, but I am not sure if it will cause an accessibility issue

[XhmikosR]

@mdo @patrickhlauke do you know if it's pointer-events: none or user-select: none or both?

[patrickhlauke]

user-select: none won't prevent images from being dragged (at least not in Chrome where I just tested it). pointer-events: none makes the whole image "transparent" to any mouse interactions, but i'd be very careful with that as it also stops legitimate things like being able to right-click to save an image etc.

long story short: I'd leave this as is and keep using JS

(and note that in our docs, we don't use actual <img> elements but <svg>, so won't be able to directly test this ... and the extra styles for docs do have user-select: none for those svgs to prevent the <text> inside them from being selectable, but that's a completely separate issue to images)