getClusterNodes RPC API now includes the node software version

[mvines]

curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "id":1, "method":"getClusterNodes"}' http://localhost:8899 | jq
{
  "jsonrpc": "2.0",
  "result": [
    {
      "gossip": "127.0.0.1:8001",
      "pubkey": "D65yPWvcqsvWAgiSkHmmpQQVykmCpSnQcqLhW7JwfnFs",
      "rpc": "127.0.0.1:8899",
      "tpu": "127.0.0.1:8003",
      "version": "1.2.0 devbuild"
    }
  ],
  "id": 1
}

Depends-on: #9981

[codecov]

Codecov Report

Merging #9990 into master will decrease coverage by 0.0%.
The diff coverage is 60.0%.

@@           Coverage Diff            @@
##           master   #9990     +/-   ##
========================================
- Coverage    80.4%   80.4%   -0.1%     
========================================
  Files         286     286             
  Lines       66369   66373      +4     
========================================
- Hits        53378   53372      -6     
- Misses      12991   13001     +10