separate mediainfo cli from gui

[gt7-void]

Installing mediainfo pulls in a lot of gui stuff, but it contains a useful cli tool (/bin/mediainfo) which doesn't require any of that stuff.

I wonder if it makes sense to split the package in mediainfo and mediainfo-gui like other distros (e.g. https://packages.debian.org/sid/mediainfo-gui).

As an example, in my system mediainfo is the only package forcing me to have libsecret installed, which is precisely what breaks {next,own}cloudclient from working with kwallet without KDE, see
#26774 (comment)