Menu component: enable dropdown to stay open after an item is selected
For the purposes of creating a multi-select dropdown menu for xpub-eLife (see pic from wireframes below), the menu component needs to be able to stay open after an item is selected
- 'open' is false by default
- a different value can be passed into handleSelect
Note: In this request there is also a slight amendment so that the component does not break if an onChange handler is not provided.