Carousel prevents input into form elements within slides

[kulbakin]

Carousel should allow input for input or textarea within slides, there is no reason why it shouldn't.

Currently carousel keydown handler calls e.preventDefault() then checks for event source tag and does nothing if it is input or textarea. It would make more sense to prevent default after this check, not before.

[cvrebert]

X-Ref: #14991

[prosanelli]

👍