Emit a warning when sort is used for range queries

[charleskorn]

Proposal

Using sort with range queries will not work: the series in a range query result will always be sorted by the series labels.

This may be confusing for users. It would be nice to emit a warning annotation when sort is used for a range query to explain what is happening.

(acknowledgement: this is @bboreham's idea from #14083 (comment))

[bboreham]

It can be expensive on CPU to sort at every step of a range-query; we could save that overhead.

sort_by_label could work for range queries, but Prometheus currently overrides that too.