[Feature Request]: Allow metrics to be tagged or segmented

### What would you like to happen?

It would be great if metrics could have some additional metadata associated with them (e.g. labels) that allows them to be grouped easily. This would allow users to query for "machine learning" metrics or "IO" metrics for example

### Issue Priority

Priority: 2 (default / most feature requests should be filed as P2)

### Issue Components

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