Favor escaping over interpolation in Underscore templates for media. Translate some strings directly instead of passing via JS.

Props nacin.
See #27574.



git-svn-id: https://develop.svn.wordpress.org/trunk@27868 602fd350-edb4-49c9-b593-d223f7449a82
Cleanup up the display, escaping, and handling of ID3 data for media. Rename `wp_get_relevant_id3_keys()` to `wp_get_attachment_id3_keys()`.

Props nacin.
See #27574.



git-svn-id: https://develop.svn.wordpress.org/trunk@27869 602fd350-edb4-49c9-b593-d223f7449a82