bonjour rd: Add bonjour renderer discovery submodule
bonjour rd: Add bonjour renderer discovery submodule

Add a bonjour renderer submodule to the bonjour service discovery
module, so it can discover chromecast renderers (for now) and others
in the future.
There is still some work needed to make it detect chromecast
capabilities correctly and to not hardcode it to chromecast.
(See the TODO comment)

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc