OptionalchooseMulti-button dialog. Resolves with the clicked option's id, or null
if the user dismisses it with Escape. The first option flagged
primary: true (or the first option, when none is flagged) is the
default action and is bound to Enter. Optional, so existing
implementations of this interface stay valid.
A simple interface for dialog wrappers that can be used to abstract away the browser's built-in dialog methods or custom implementations.