Adding GELF logging protocol for logDestinations

[Creepios]

Describe the feature

Implement the feature, that you can publish log ("logDestinations") with GELF protocol (Graylog Extended Log Format) to a remote log server. https://go2docs.graylog.org/current/getting_in_log_data/gelf.html In my opinion, it would be very useful that you can live analyze logs in a very clearly arranged software like Graylog, especially when you have multiple mediamtx application running at the same time.