build(deps-dev): bump node-sass from 4.14.1 to 5.0.0 in /frontend

Bumps [node-sass](https://github.com/sass/node-sass) from 4.14.1 to 5.0.0.
- [Release notes](https://github.com/sass/node-sass/releases)
- [Changelog](https://github.com/sass/node-sass/blob/master/CHANGELOG.md)
- [Commits](sass/node-sass@v4.14.1...v5.0.0)

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

Author: dependabot[bot]

frontend/package.json

@@ -39,7 +39,7 @@
     "file-loader": "^6.0.0",
     "html-webpack-plugin": "^4.0.1",
     "mini-css-extract-plugin": "^1.0.0",
-    "node-sass": "^4.12.0",
+    "node-sass": "^5.0.0",
     "optimize-css-assets-webpack-plugin": "^5.0.3",
     "prettier": "1.19.1",
     "sass-loader": "^10.0.1",