[UX] fade out non-playable streams (!is_web_ready()), but show an indicator

[Ivshti]

if there are streams which are not currently playable (cause of incompatible protocol or format), the streams component should fade them out and render a "N streams unavailable because they are not compatible with your current platform" at the top, with an explanation when you click on it

If you click on a faded out stream, you should get the same explanation

The explanation should contain what you can do (connect a streaming server)

related to https://github.com/Stremio/stremio-web/issues/142 and described in Stremio/stremio#655