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/player/.editorconfig

@@ -0,0 +1,18 @@
+# editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+indent_style = tab
+indent_size = 1
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[package.json]
+indent_style = space
+indent_size = 2
+
+[*.md]
+insert_final_newline = true
+trim_trailing_whitespace = false