Icon: Ensure color property works with SCSS

[solittlework]

Background Info

We cannot change the colour in the GoAIcon through the interface provided. However, most of the icons presented in the design mock comes with a non-black colour.

Acceptance Criteria

1. New property color for Icon component
2. Should accept:
   • info -- --goa-color-info-default
   • warning -- --goa-color-warning-default
   • emergency -- --goa-color-emergency-default
   • success -- --goa.color.success.default
   • light -- --goa-color-greyscale-white
   • dark -- --goa-color-greyscale-black
   • and a custom hex value
   • and a custom rgb value
   • or any design token

[ArakTaiRoth]

@solittlework We've updated this feature request to add proper acceptance criteria. If you want to take a look and let us know if there's anything we're missing.

[ArakTaiRoth]

This has been completed, and is provided with the fillColor property