Youtube videos in content

[simesy]

As a content editor i want to embed videos (media entities) into ckeditor, and to add a "hero" video alongside the hero image. I want to control the way these are displayed.

Acceptance criteria:

1. Videos are added as media entities ("remote video" media type already exists)
2. I can add a video as a "hero" video (not used for anything yet)
3. I can add videos to ckeditor and they display nicely inline (full width) in the article. At the table breakpoint they jut into sidebar the side the way images do.)
4. There is a video media item in the default content provided by fs_test module.