[BUGFIX] Improve usability of new Media element flexform

With HTML5 video many new options are added to the media element
flexform. This results in a very hard to read form.

Restructure the fields into tabs and use display conditions
to hide unneeded fields depending on the selected media type.

Change-Id: I1a25a17506541a3461bcd83d320a395bad3f8195
Fixes: #35433
Releases: 6.0,4.7
Reviewed-on: http://review.typo3.org/10109
Reviewed-by: Dominik Mathern
Tested-by: Dominik Mathern
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter
Reviewed-on: http://review.typo3.org/10223