✨ elevation options to Card/Banner/TopBar

[oddvernes]

resolves #2230

as per design directives, the allowed elevations are:
TopBar: none, raised
Banner: none, raised, overlay
Card: none, raised, overlay

This pr also removes max/min width on Paper

[mimarz]

This is the type that users will see in their IDE, so maybe a nicer word, availableElevations ? Its also a type which means it should start with an Uppercase.

[oddvernes]

Changing it to AvailableElevations

[mimarz]

After changing this to use Paper it doesn't look like its a header element anymore. Maybe use the as prop to cast it here?

[oddvernes]

I have now learned about forwardedAs since using as on an element also extended with styled(component) will not work

[mimarz]

Suggest removing this or set it to none as thats the default elevation for Topbar

[oddvernes]

The example is a sticky topbar though, which is the use case where it should be elevated. Perhaps the main example should not be sticky and move that down as its own story?

[oddvernes]

eh, I just removed it

[mimarz]

LGTM 👍