Popup: the PopupContent inside the Popup cannot be styled or augmented with some user defined props

[mnajdova]

Feature Request

Problem description

The content of the Popup cannot be styled using any props in the Popup. Moreover the user cannot provide any properties to that component at all. In order to style it, the user have to wrap it with Provider and provide the styles for the PopupContent component there in the following manner:

<Provider theme={{ componentStyles: { PopupContent: { root: { marginLeft: '10px' } } } }}>
  <Popup
    {...props}
  />
</Provider>

Proposed solution

The PopupContent should be shorthand inside the Popup so that the user can apply any properties they want on that slot of the component.