CostManagement Query grouping by Tag produces empty column

Hello, I am attempting to include tags (both keys and values) in the grouping for the results from the Query endpoint. I have attempted to use `grouping` and the `configuration` items. Using the grouping results in the `Tag` column being present in the data, but all of the values are just `""`. I was following instructions from this thread https://github.com/Azure/azure-rest-api-specs/issues/12158#issuecomment-758238927

Request Body:

```
{
"type": "Usage",
"timeframe": "Custom",
"timePeriod": {
"from": ...,
"to": ...
},
"dataset": {
"granularity": "Daily",
"aggregation": {
"totalCostUSD": {
"name": "CostUSD",
"function": "Sum"
}
},
"grouping": [
{
"type": "Tag"
},
{
"type": "TagKey"
},
{
"type": "TagValue"
},
{
"type": "Dimension",
"name": "ResourceGroupName"
},
{
"type": "Dimension",
"name": "ChargeType"
},
{
"type": "Dimension",
"name": "ResourceId"
},
{
"type": "Dimension",
"name": "MeterCategory"
},
{
"type": "Dimension",
"name": "MeterSubcategory"
},
{
"type": "Dimension",
"name": "Meter"
},
{
"type": "Dimension",
"name": "SubscriptionId"
},
{
"type": "Dimension",
"name": "ResourceLocation"
}
]
}
}
```

Start with the Cost Management Query endpoint and compare the reported request with the guidance in the linked azure-rest-api-specs issue. Reproduce the grouping request and inspect the Cost Management API specification for Tag, TagKey, and TagValue behavior. Done means identifying and correcting the specification issue, or documenting that the service does not return tag values as requested.

Written by the indexing model from the issue text.