Add support for className when icon has background

[brugaspar]

Add support for className when icon has weight "fill" or "duotone". When you set weight to thin, light, regular or bold, the className works fine, because the "fill" prop in SVG is currentColor, but when the weight is fill or duotone, the "fill" prop in SVG is set to props.color, losing the color passed through className.

I'm using Nativewind, so when I use something like "text-zinc-800", it only works with weights that don't have background, e.g. regular.

I did some tests and I think this could be removed, since "currentColor" works for both "fill" and "duotone" as well.