[ARGUS] Change Argus Label to JSON format

[Carter Bullard]

Gentle people,
As we transition work from other projects into the open source code base, there are a few specific changes to the argus data formats that I’d like to make.  One of the most important is the argus label.  I’d like to transition the label to JSON format.  We have some native JSON library routines now, (added in argus-clients.3.0.8.4) and as a metadata format, its a bit more familiar than the metadata standard that argus uses now.

I’d like to propose an ARGUS_LABEL_FORMAT variable for the rarc file, to specify which format this client will output its data in.
The option syntax would be:
   ARGUS_LABEL_FORMAT=[ LEGACY | JSON ]

In the implementation, we’d be able to read all label formats, and have the option to write out any format. 
If the format is not set, in new releases of Argus 3.0 data, we’ll write out the format that we receive.

In Argus 4.0, the default label format will be JSON.

I’ll add the variable to the rarc configuration in the next release, which would be argus-clients 3.0.8.6 (we’re on argus-clients 3.0.8.4 now) …
We’ll be on Argus 4.0 by June, 2022.

If this is agreeable, I’ll put in the rarc variable support now ...
Hope all is most excellent,

Carter