Bug 15225: Make HTML5Media work with file upload feature.

Bug 15225: Make HTML5Media work with file upload feature.

Koha::Upload allows files to be attached to bibliographic records.
HTML5Media streaming in Koha does not work with these files.

Test plan:
- apply patch
- make sure OPACBaseURL is set correctly
- enable HTML5MediaEnabled in OPAC and staff client
- connect upload.pl to 856$u in your framework
- upload a file with an extension set in HTML5MediaExtensions,
  make sure to set the codec correctly if you use WEBM (subfield c,
  eg. 'vp8, vorbis')
- save record, view in staff client and browser, check if 'Play
  media' option is available and works

Signed-off-by: Hugo Agud <hagud@orex.es>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>