* Prometheus: Add metadata to metrics in Metrics browser
- use the available metadata to enhance the tooltip on metric items in the metrics browser
- added meta info for histogram metrics (was missing before)
- also added one for ALERTS
* fix test
* WIP, works but need to do more testing
* Update solution
* Fix autocomplete with metrics
* Update public/app/plugins/datasource/prometheus/language_provider.ts
* Update public/app/plugins/datasource/prometheus/language_provider.ts
* Change test for new functionality
* First pass solution
* Refactor solution
* Add test coverage, update tests
* Fix behaviour for multiple labels, add test for this
* Add recordin rules to devenv prometheus
* Update devenv/prometheus2 instead of devenv/prometheus
* Add newlines
* Fix label matching if labels include comma, add test coverage
* Refactor
* Refactor, simplify
* Prometheus: Add metadata for summary metrics
- summary metrics don't have metadata available from the metadata API,
so Grafana can help and just add it
- given a summary metric `foo`, we add metadata info for `foo_sum` and
`foo_count`
- with tests
* Update public/app/plugins/datasource/prometheus/language_utils.ts
Co-authored-by: gotjosh <josue@grafana.com>
Co-authored-by: gotjosh <josue@grafana.com>
