mediainfo: Add package and dependencies

Includes only the CLI version and the following dependencies:

 * libzen
 * libmediainfo
mediainfo: Add myself to meta.maintainers.
mediainfo-gui: Add package
libzen: Add --enable-shared to configureFlags.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Merge pull request #5389 from devhell/mediainfo.

Introduces a video/audio information utility, both CLI and GUI.

Thanks to @devhell.

* devhell-mediainfo:
  libzen: Add --enable-shared to configureFlags.
  mediainfo-gui: Add package
  mediainfo: Add myself to meta.maintainers.
  mediainfo: Add package and dependencies