Support /api/v1/parse_query API (Experimental)

[friedrichg]

Is your feature request related to a problem? Please describe.
Dashboard tools, in this specific case perses, might relay on this prometheus API part to parse the query.

Describe the solution you'd like
Query frontend should handle this part

Describe alternatives you've considered
None

Additional context
Yes, it's experimental, but we should implement it per https://www.hyrumslaw.com/ ;)
https://prometheus.io/docs/prometheus/latest/querying/api/#parsing-a-promql-expressions-into-a-abstract-syntax-tree-ast

[friedrichg]

The treeview feature is enabled with this perses/perses#2420 (comment)

[yeya24]

This API is already supported and exposed by Prometheus API Router.
I agree it is better to handle it in Query Frontend only but we should be able to enable it today on both Query Frontend and Querier by registering the route here.

[pnijem]

Hi

Does this issue still require handling? If so, can I take it?