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/src/static/js/utils/actions/PageActions.js

@@ -0,0 +1,22 @@
+import Dispatcher from '../dispatcher.js';
+
+export function initPage(page) {
+  Dispatcher.dispatch({
+    type: 'INIT_PAGE',
+    page,
+  });
+}
+
+export function toggleMediaAutoPlay() {
+  Dispatcher.dispatch({
+    type: 'TOGGLE_AUTO_PLAY',
+  });
+}
+
+export function addNotification(notification, notificationId) {
+  Dispatcher.dispatch({
+    type: 'ADD_NOTIFICATION',
+    notification,
+    notificationId,
+  });
+}