Refs #21467; added body font-size in order to lower the size of the embed type to match more of the text size of the chart
Refs #21467; embed_chart ux improvements:

- Added show and hide icons to the share-spritesheets image
- Moved share logic to embed_common since it will be used also by the
  dashboard embed. Better caching and debugging is also available now that
  the js is moved out of the template
- Added functionality that shows and hides the actions div in order to
  avoid content overlap on chart hover
- Fixed multiple chart embed code