Bump underscore from 1.10.2 to 1.12.1 in /frontend

Bumps [underscore](https://github.com/jashkenas/underscore) from 1.10.2 to 1.12.1.
- [Release notes](https://github.com/jashkenas/underscore/releases)
- [Commits](https://github.com/jashkenas/underscore/compare/1.10.2...1.12.1)

Signed-off-by: dependabot[bot] <support@github.com>

frontend/package.json

@@ -34,7 +34,7 @@
     "sass-loader": "^8.0.2",
     "style-loader": "^1.1.3",
     "tabler-ui": "git+https://github.com/tabler/tabler.git#00f78ad823311bc3ad974ac3e5b0126198f0a813",
-    "underscore": "^1.10.2",
+    "underscore": "^1.12.1",
     "webpack": "^4.42.1",
     "webpack-cli": "^3.3.11",
     "webpack-visualizer-plugin": "^0.1.11"