chore(deps): bump node-sass from 5.0.0 to 7.0.0 in /frontend

Bumps [node-sass](https://github.com/sass/node-sass) from 5.0.0 to 7.0.0.
- [Release notes](https://github.com/sass/node-sass/releases)
- [Changelog](https://github.com/sass/node-sass/blob/master/CHANGELOG.md)
- [Commits](sass/node-sass@v5.0.0...v7.0.0)

---
updated-dependencies:
- dependency-name: node-sass
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>