Correct descriptions and legend for TDG specific metrics

[opomuc]

TDG specific iproto latency metric is displayed as microseconds, but calculated as milliseconds.

Dimensions for iproto should be changed at least. I would also suggest checking other TDG specific metics.

TDG iproto metric calculation

part of dashboard's JSON. look at yaxes.format

{
...
          "description": "99th percentile of repository.put IProto call execution time.\n",
...
          "targets": [
            {
              "expr": "tdg_iproto_data_query_exec_time{job=~\"$job\",alias=~\"$alias\",method=\"repository.put\",quantile=\"0.99\"}",
              "format": "time_series",
...
            }
...
          "xaxis": {
            "buckets": null,
            "mode": "time",
            "name": null,
            "show": true,
            "values": []
          },
          "yaxes": [
            {
              "decimals": 0,
              "format": "µs",
              "label": "99th percentile",
              "logBase": 1,
              "max": null,
              "min": null,
              "show": true
            },
            {
              "decimals": 3,
              "format": "µs",
              "label": null,
              "logBase": 1,
              "max": null,
              "min": null,
              "show": true
            }
          ]
        },