Bump node-sass from 4.5.0 to 4.14.1 in /frontend

Bumps [node-sass](https://github.com/sass/node-sass) from 4.5.0 to 4.14.1.
- [Release notes](https://github.com/sass/node-sass/releases)
- [Changelog](https://github.com/sass/node-sass/blob/master/CHANGELOG.md)
- [Commits](sass/node-sass@v4.5.0...v4.14.1)

---
updated-dependencies:
- dependency-name: node-sass
  dependency-type: indirect
...

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

Author: dependabot[bot]