mwax_subfile_distributor health JSON format

Health data is sent via multicast UDP and is in the following format:

{
   "main":{
      "process":"MWAXSubfileDistributor",
      "version":"X.Y.Z",
      "host":"Hostname",
      "running":"True|False",
      "beamformer":"True|False",
      "beamformer archiving":"True|False",
      "correlator":"True|False",
      "correlator archiving":"True|False",
      "processors":[
         {
            "type":"SubfileProcessor",
            "watchers":[
               {
                  "name":"subfile watcher",
                  "watching":"True|False",
                  "mode":"MODE_WATCH_DIR_FOR_NEW | MODE_WATCH_DIR_FOR_RENAME",
                  "watch_path":"/dev/shm/mwax",
                  "watch_pattern":".sub",
                  "watch_used_bytes":"USED_BYTES",
                  "watch_free_bytes":"FREE_BYTES"
               }
            ],
            "workers":[
               {
                  "name":"subfile worker",
                  "current":null,
                  "queue_size":0
               }
            ]
         },
         {
            "type":"MWAXArchiveProcessor",
            "archiving":"running | stopped",
            "watchers":[
               {
                  "name":"voltdata_watcher",
                  "watching":"True|False",
                  "mode":"WATCH_DIR_FOR_NEW | MODE_WATCH_DIR_FOR_RENAME",
                  "watch_path":"/voltdata",
                  "watch_pattern":".sub",
                  "watch_used_bytes":"USED_BYTES",
                  "watch_free_bytes":"FREE_BYTES"
               },
               {
                  "name":"visdata_watcher",
                  "watching":true,
                  "mode":"WATCH_DIR_FOR_NEW | MODE_WATCH_DIR_FOR_RENAME",
                  "watch_path":"/visdata",
                  "watch_pattern":".fits",
                  "watch_used_bytes":"USED_BYTES",
                  "watch_free_bytes":"FREE_BYTES"
               }
            ]
         }
      ]
   }
}