- add missing defaults
- add missing Picked props :| (storybook why?? need to figure this out)

- add support for `onCreateOption` UX
- make story `onChange` and `onCreateOption` show up in actions pane

- use generic for nav or div DOM element type instead of casting `as`

- add missing control defaults

- register onClose action in storybook tab

- not used by any other Elastic products, and unlikely to be used standalone

+ fix missing `children` in exported EuiContextMenuItemProps

- there's a lot of TODOs at the bottom here because this is honestly kind of a weird component that feels very legacy