Draft: Lint SVG filenames

Purpose

Adds the ls-lint npm package and config to enforce standardized file names.

• This is configured to require that SVG files have kebab-case filenames (only lowercase letters, digits and - allowed).
• If files are not named correctly, the build-and-check CI job will not pass.

Example failed job before renaming the offenders: https://gitlab.com/gitlab-org/gitlab-svgs/-/jobs/3341721508

Closes #311 (moved)