Bump lodash from 4.17.15 to 4.17.21 in /js

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.15 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.15...4.17.21)

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

Author: dependabot[bot]

js/package-lock.json

@@ -57,7 +57,7 @@
     "@types/node": "^12.6.9",
     "ajv": "^6.10.2",
     "css-loader": "^3.2.0",
-    "lodash": "^4.17.15",
+    "lodash": "^4.17.21",
     "npm": "^6.14.6",
     "source-map-loader": "^0.2.4",
     "style-loader": "^1.0.0",