We relocated window measurment logic into a hook, useGridSpans(), which
tells us the appropriate number of columns for the IconGrid. This is
useful for rendering an InfoPanel in the right place! In future we
should look into a custom implementation using ResizeObserver and
polyfills, and that may be extensible for other use-cases.
This is now in compliance with the spec, using a single color with
opacity to render open/hovered/active GridItems and InfoPanels. We also
properly show background on open GridItems.
This patch extracts InfoPanel from IconGridItem, adds style tweaks to
match the spec, and in general reduces prop-drilling by tapping into
recoil state for most config, and making use of IconContext to style
member icons where appropriate :)
