Feature/grs 1955 change commonjs imports (#1995)

* GRS-1955: Using ES6 import/export in src files

* GRS-1955: Using ES6 import/export in test files

* GRS-1955: Using ES6 import/export in themes index.js

* GRS-1955: Readding blank line at end of top-languages-card.js

* feat: fix test es6 import errors

This commit makes sure jest is set-up to support es6. It also fixes
several test errors and sorts the imports.

* test: update test node version

This commit makes sure node 16 is used in the github actions.

* refactor: run prettier

Co-authored-by: rickstaa <rick.staa@outlook.com>

scripts/generate-langs-json.js

@@ -1,6 +1,6 @@
-const fs = require("fs");
-const jsYaml = require("js-yaml");
-const axios = require("axios");
+import axios from "axios";
+import fs from "fs";
+import jsYaml from "js-yaml";
 
 const LANGS_FILEPATH = "./src/common/languageColors.json";