SearchControl: Deprecate onClose prop

[mirka]

What problem does this address?

The onClose prop is not used anymore in the Gutenberg app. It was originally intended to render a close button to "trigger your own logic to close the search field entirely, rather than just clearing the input value."

The prop itself is causing confusion to consumers (#64921), and I think the UI pattern of a single button that doubles as a reset and a close is questionable from a UX standpoint.

What is your proposed solution?

I think we can soft deprecate the feature. For consumers that really want to maintain the original behavior, however unrecommended, we can issue guidance to use the suffix prop.

[ciampo]

we can issue guidance to use the suffix prop.

Agreed. We could add a dedicated Storybook example too