Inconsistent icon direction on sortable table

[andesol]

After https://github.com/canonical/vanilla-framework/pull/5135 that inverted the icons on the sortable table, seems like it needs to be updated on the react components as well, otherwise the direction doesn't match.

Compare this example: https://vanillaframework.io/docs/examples/patterns/tables/table-sortable?theme=light

With this one: https://canonical.github.io/react-components/?path=/story/components-maintable--sortable