Missing fields in MetricQueryMetadata struct

[arjunmahishi]

Describe the bug
There are a couple of fields missing in the MetricQueryMetadata struct. These are also missing in the documentation.

Here is the actual response I am getting from the GET /api/v1/query endpoint:

{
    "end": 1622526239000,
    "attributes": {},
    "metric": "custom.load.1",
    "interval": 120,
    "tag_set": [
        "key1:tag1"
    ],
    "start": 1622504760000,
    "length": 96,
    "query_index": 0,
    "aggr": null,
    "scope": "key1:tag1",
    "pointlist": [
    ],
    "expression": "custom.load.1{key1:tag1}",
    "unit": null,
    "display_name": "custom.load.1"
}

As you can see these fields are missing from the struct and the documentation:

• attributes
• tag_set
• query_index

Environment and Versions (please complete the following information):
A clear and precise description of your setup:

• version for this project in use: v1.0.0-beta.22

[hydrosquall]

@arjunmahishi thanks for the report, we've added documentation for tag_set and query_index in #979 .

The attributes field is more complex (when populated, it contains fields that are populated by certain expression types that are subject to change). We're looking into it separately.

[arjunmahishi]

Thanks! :)