Add return type option for TLS/CLS/FLS commands

[eol-account]

Requested in #14

Adds the config option <response-format> to <media-server>. Takes SDL (default), JSON, or XML

[Julusian]

I am currently thinking that we shouldnt include this, as this will easily cause confusion and break existing clients, and when relayed back to any clients over amcp does break the format that amcp is expected to be in.

Personally, I think a better approach is for the clients that want this enhanced data to connect directly to the scanner over http. It does add some complexity for deployment/firewalls, but it will slightly reduce the load on casparcg and allow for more advanced things to be done between the scanner and any clients.

Or I wouldnt be opposed to this being done as a parameter passed through amcp, to specify the encoding. If someone wants to rework this to do that and open a new pr, that could be accepted