* Refactor Explore query field
- extract typeahead field that only contains logic for the typeahead
mechanics
- renamed QueryField to PromQueryField, a wrapper around TypeaheadField
that deals with Prometheus-specific concepts
- PromQueryField creates a promql typeahead by providing the handlers
for producing suggestions, and for applying suggestions
- The `refresher` promise is needed to trigger a render once an async
action in the wrapper returns.
This is prep work for a composable query field to be used by Explore, as
well as editors in datasource plugins.
* Added typeahead handling tests
- extracted context-to-suggestion logic to make it testable
- kept DOM-dependent parts in main onTypeahead funtion
* simplified error handling in explore query field
* Refactor query suggestions
- use monaco's suggestion types (roughly), see
https://github.com/Microsoft/monaco-editor/blob/f6fb545/monaco.d.ts#L4208
- suggest functions and metrics in empty field (ctrl+space)
- copy and expand prometheus function docs from prometheus datasource
(will be migrated back to the datasource in the future)
* Added prop and state types, removed unused cwrp
* Split up suggestion processing for code readability
- new builtin datasource plugin "Logging" (likely going to be renamed)
- plugin implements no panel ctrls yet, only ships datasource
- new models for logging data as first class citizen (aside from table
and time_series model)
- Logs as new view for Explore
- JSON view for development
Testable only against existing logish deployment.
Then test with queries like `{job="..."} regexp`.
* style header like other grafana components
* use panel container for graph and same styles for query field
* fix typeahead CSS selector (was created outside of .explore)
* use navbar buttons for +/- of rows
* moved elapsed time under run query button
* fix JS error on multiple timeseries being returned
* fix color for graph lines
* show prometheus query errors
