* Prometheus: user metrics metadata to inform query hints
- no longer analyse datapoints
- either use metrics metadata to determine metrics type or use metric
name suffix
- removed testcases based on datapoints
* Added hint certainty and tests
* Chore: Remove implicit anys from ResultProcessor and tests
* Chore: Removes implicit anys for /loki/**/*.ts
* Chore: Removes implicit anys for prometheus/**/*
- since the DataQuery rewrite, Explore starts by submitting its queries (Explore cant know if the queries are emtpty)
- The datasource intercepts an empty query and returns an empty list of time series, and also no table for the table query.
- The query hinter then received no series to analyse and was not guarding against this.
- This PR adds this guard.
Implements rudimentary support for placeholder values inside a string
with the `PlaceholdersBuffer` class. The latter helps the newly added
sum aggregation query suggestion to automatically focus on the label
so users can easily choose from the available typeahead options.
Related: #13615
