Add a more stable path for Ink image assets.

Review Request #13939 — Created June 5, 2024 and discarded — Latest diff uploaded




We had an @images-path variable in LessCSS that was used to link to
the Ink images, but this had a couple of problems. One is that the name
was too generic and likely to conflict with consuming packages. The
other is that it pointed to "ink", which wasn't likely to resolve well
in practice anywhere.

We now have an @ink-path variable that points to @beanbag/ink, and w
use that to build paths as necessary.

This means no images-specific variable, so the references now compensate
by including the images directory in the referenced path.

Tested the images in Storybook, making sure they loaded.

Successfully built packages.