Replace FAO area icons with static images

[GalMunGral]

These icons are currently rendered at run-time from FAO area GeoJSON by the RegionIcon component:

challenger-portal/src/components/Explore/LeftSidebar/StationList/RegionIcon.tsx

Line 15 in 8ab4281

const RegionIcon: FC<Props> = ({ faoArea, size = 64, opacity = 1 }) => {

challenger-portal/src/components/Explore/LeftSidebar/StationList/index.tsx

Line 123 in 8ab4281

<RegionIcon size={62} faoArea={group.faoArea} />

We should replace the RegionIcon component with static images once the design is ready.