The `<ModalContainer />` component. This component is primarily used as a wrapper for other
components.

The `showArrow` and `placement` prop of this `<ModalContainer/>` together are only necessary for the
Popover component, where the Arrow and the positioning are highly important. Using the
`<ModalContainer/>` component standalone with the `placement` and `showArrow` props will just paint,
but not position the arrow correctly (done through Popover component).

Nevertheless this component could be used on its own as well.