net/gerbera: New port, UPnP/DLNA media server

Gerbera is a DLNA compatible media server and a continuation of MediaTomb
It allows you to browse and playback your media via your network, supports
metadata extraction, media thumbnail support and generation, media transcoding
and offers a Web UI.

WWW: https://gerbera.io/

PR: 248475
Submitted by: daniel.engberg.lists@pyret.net
Reviewed by: meena