use camel case for proto messages

[cendhu]

When we use abc_efg pattern to define a field name in the proto, the json tag would be the same as abc_efg and the field would get a camel case name, i.e., AbcEfg. While this is okay, even in the proto message, we have used mix of camel case and abc_efg pattern in places to get ID or DB instead of Id or Db (to avoid linter warnings). As a result, the json tags contains mix of fields names with _ and camel case.

Hence, we need to use a single pattern consistently to improve the usability.

An example JSON format is shown below for a config tx: (userID, txID, ID, block_num, etc...)

{
  "payload": {
    "userID": "admin",
    "txID": "1b6d6414-9b58-45d0-9723-1f31712add79",
    "read_old_config_version": {
      "block_num": 1,
      "tx_num": 0
    },
    "new_config": {
      "nodes": [
        {
          "ID": "bdb-node-1",
          "address": "127.0.0.1",
          "port": 6001,
          "certificate": "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"
        },
        {
          "ID": "bdb-node-2",
          "address": "127.0.0.2",
          "port": 6002,
          "certificate": "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"
        }
      ],
      "admins": [
        {
          "ID": "admin",
          "certificate": "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"
        }
      ],
      "rootCA_certificate": "MIIBSjCB8AIJALVOgMaBCfQLMAoGCCqGSM49BAMCMC0xCzAJBgNVBAYTAlVTMQswCQYDVQQIDAJOSjERMA8GA1UECgwIQ0EsIEluYy4wHhcNMjAwNzI5MDQ0MDU3WhcNMzAwNzI3MDQ0MDU3WjAtMQswCQYDVQQGEwJVUzELMAkGA1UECAwCTkoxETAPBgNVBAoMCENBLCBJbmMuMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEOQgOfb8X1GU8vdxSDW7KjCSRhjshDwKHgf6T3m0YhebGRQS1ey0eAXEVopWmxJJHBu1ETfT26eBjtxJ+5kmRojAKBggqhkjOPQQDAgNJADBGAiEAx/8k4agfLJywKgktChASTZOXTddc9S9xF24ZuQ7xF28CIQC8TG/lhVRWUaTUTUYGpdSp6tJVLf86xBW2d+h4GtcEhQ=="
    }
  },
  "signature": "aGVsbG8="
}