Add `selected_icon` to `IconButton` (#3477)

This PR adds a new `selected_icon` method to `IconButton`.

This can be used to set a different icon that should be rendered when
the `IconButton` is selected.

Release Notes:

- N/A
4f507756d6Marshall Bowers committed on 12/1/2023, 6:17:32 PM· committed by GitHubparentsbe5eb3e12b58f5
3 files changedLine totals unavailable