components+hooks: refactor window measurement

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.

src/components/IconGrid/IconGridItem.tsx

@@ -79,7 +79,6 @@ const IconGridItem: React.FC<IconGridItemProps> = (props) => {
           backgroundColor: isOpen ? "rgba(163, 159, 171, 0.1)" : undefined,
         }}
         custom={delayRef}
-        // whileTap={whileTap}
         transition={transition}
         variants={itemVariants}
         onKeyPress={(e) => e.key === "Enter" && handleOpen()}