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

static/css/embed.css

@@ -1 +1 @@
-.player-container{overflow:hidden;background:#000}.embed-wrap{position:fixed;top:0;left:0;right:0;bottom:0;display:block}.embed-wrap .player-container,.embed-wrap .player-container-inner{width:100%;height:100%}
+.player-container{overflow:hidden;background:#000}