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/vjs-plugin-font-icons/lib/custom2.json

@@ -0,0 +1,6 @@
+{
+  "icons": [{
+    "name": "sunny",
+    "svg": "image/svg/production/ic_wb_sunny_48px.svg"
+  }]
+}