Occasionally send the Warcprox status to the server

[TheTechRobo]

This way we can use it in !status!

It can just be stored in RAM, I guess - no DB necessary.

Example JSON for /status

{
  "role": "warcprox",
  "version": "2.4.17",
  "host": "themandownstairs",
  "address": "127.0.0.1",
  "port": 4551,
  "pid": 213414,
  "threads": 100,
  "active_requests": 2,
  "unaccepted_requests": 0,
  "load": 0.0,
  "queued_urls": 0,
  "queue_max_size": 500,
  "urls_processed": 17,
  "warc_bytes_written": 321401,
  "start_time": "2022-10-10T18:16:04.785443+00:00",
  "rates_1min": {
    "actual_elapsed": 63.26238942146301,
    "urls_per_sec": 0.26872206623027767,
    "warc_bytes_per_sec": 5080.443576969263
  },
  "rates_5min": {
    "actual_elapsed": 13.262403011322021,
    "urls_per_sec": 1.2818189875158534,
    "warc_bytes_per_sec": 24233.994376857812
  },
  "rates_15min": {
    "actual_elapsed": 13.262410402297974,
    "urls_per_sec": 1.2818182731741143,
    "warc_bytes_per_sec": 24233.980871554915
  },
  "earliest_still_active_fetch_start": "2022-10-10T18:16:17.963828+00:00",
  "seconds_behind": 0.102504,
  "postfetch_chain": [
    {
      "processor": "DedupLoader",
      "queued_urls": 0
    },
    {
      "processor": "WarcWriterProcessor",
      "queued_urls": 0
    },
    {
      "processor": "DedupDb",
      "queued_urls": 0
    },
    {
      "processor": "StatsProcessor",
      "queued_urls": 0
    },
    {
      "processor": "CrawlLogger",
      "queued_urls": 0
    },
    {
      "processor": "RunningStats",
      "queued_urls": 0
    }
  ]
}

[TheTechRobo]

We could also make it ping the client directly and ask it for the details right at that moment, which would be more efficient server-side. Might be tricky to implement though.