Log version on start

[Pesa]

We should log the version number (or commit hash) when the service starts, to facilitate debugging issues and helping users who provide the logs but not the version they are running. Other key info on the platform, environment, and/or versions of other key dependencies could potentially be included as well (saves one Q&A roundtrip).

[yoursunny]

This is applied to ndndpdk-svc command. Sample output:

{
  "level": "info",
  "ts": 1629734705.6987371,
  "logger": "main",
  "msg": "NDN-DPDK service starting",
  "version": "v0.0.0-20210823160036-1f3a732fac8e",
  "uid": 0,
  "linux": "5.4.0-81-generic",
  "dpdk": "DPDK 21.08.0",
  "spdk": "SPDK v21.07"
}

[yoursunny]

Done in 1f3a732fac8ec638e178dd1895583003d4a72b3b