FIX: website/cbsnews: Adapt to website changes

This is a rough backport of the similar changes [6a265a9998] made to the
0.9 series. Unlike the 0.9 script however, this one will return only one
stream.

- Rewrite `ident' function
  - Script now returns HTTP/RTMP media streams
  - Script now returns only one stream
  - Add support for new input URL paths

- Simplify `query_formats' function
  - Script now returns only one stream

- Rewrite `parse' function
  - Simplify stream parsing: only one stream ("desktop") is now returned
  - Parse the media properties from the video page HTML

Signed-off-by: Toni Gundogdu <legatvs@gmail.com>
tests: default/cbsnews: Update

Signed-off-by: Toni Gundogdu <legatvs@gmail.com>
Merge branch 'tg/maint__fix_website/cbsnews' into maint-0.4