Frontent dev env (#247)

* Added frontend development files/environment

* More items-categories related removals

* Improvements in pages templates (inc. static pages)

* Improvements in video player

* Added empty home page message + cta

* Updates in media, playlist and management pages

* Improvements in material icons font loading

* Replaced media & playlists links in frontend dev-env

* frontend package version update

* chnaged frontend dev url port

* static files update

* Changed default position of theme switcher

* enabled frontend docker container

frontend/packages/scripts/cli.js

@@ -0,0 +1,47 @@
+#!/usr/bin/env node
+
+const spawn = require('cross-spawn');
+
+('use strict');
+
+// Makes the script crash on unhandled rejections instead of silently
+// ignoring them. In the future, promise rejections that are not handled will
+// terminate the Node.js process with a non-zero exit code.
+process.on('unhandledRejection', (err) => {
+  throw err;
+});
+
+const args = process.argv.slice(2);
+
+const scriptIndex = args.findIndex(
+  (x) => x === 'build' || x === 'development' || x === 'analyzer' || x === 'rimraf' // TODO
+);
+const script = scriptIndex === -1 ? args[0] : args[scriptIndex];
+const nodeArgs = scriptIndex > 0 ? args.slice(0, scriptIndex) : [];
+
+if (['build', 'development', 'analyzer', 'rimraf'].includes(script)) {
+  const result = spawn.sync(
+    process.execPath,
+    nodeArgs.concat(require.resolve('./scripts/' + script)).concat(args.slice(scriptIndex + 1)),
+    { stdio: 'inherit' }
+  );
+  if (result.signal) {
+    if (result.signal === 'SIGKILL') {
+      console.log(
+        'The build failed because the process exited too early. ' +
+          'This probably means the system ran out of memory or someone called ' +
+          '`kill -9` on the process.'
+      );
+    } else if (result.signal === 'SIGTERM') {
+      console.log(
+        'The build failed because the process exited too early. ' +
+          'Someone might have called `kill` or `killall`, or the system could ' +
+          'be shutting down.'
+      );
+    }
+    process.exit(1);
+  }
+  process.exit(result.status);
+} else {
+  console.log('Unknown script "' + script + '".');
+}