get-metric-data.js needs to provide a label decoder and a metric-source and metric-type

[atheurer]

The label decoder tells the user how to read the metric labels. Currently we have something like:

{
  "breakouts": [],
  "values": {
    "<worker>-<1>-<0>-<IR-PCI-MSI>": [
      {
        "begin": 1614636100924,
        "end": 1614636161183,
        "value": "2.153e+5"
      }
    ]
  }
}

We need to include something like:

{
 "source": "procstat",
 "type": "interrupts-sec"
 "label": "<cstype>-<csid>-<package>-<type>",
 "breakouts": [],
  "values": {
    "<worker>-<1>-<0>-<IR-PCI-MSI>": [
      {
        "begin": 1614636100924,
        "end": 1614636161183,
        "value": "2.153e+5"
      }
    ]
  }
}

[atheurer]

fixed with #29