Explore: Adds Loki explore query editor (#21497)

* Explore: updates grafana-data explore query field props with explore mode

* Explore: updates query row to pass down explore mode to query fields

* Explore: adds LokiExploreQueryEditor

* Explore: updates loki query field form to render children

* Explore: adds loki explore extra field component

* Explore: adds extra field element to loki query field form

* Explore: updates loki explore query editor to use extra field element

* Explore: moves ExploreMode to grafana-data

* Explore: updates query row limit string

* Explore: adds maxLines to DataQuery

* Explore: adds maxLines to loki datasource runRangeQueryWithFallback

* Explore: adds onChangeQueryLimit to LokiExploreQueryEditor

* Explore: updates loki explore query editor to render extra field only in logs mode

* Explore: fixes query limits for live and legacy queries

* Explore: fixes result processor max lines limit in get logs result

* Explore: fixes Loki datasource limit test

* Explore: removes unnecessary ExploreMode from Loki language provider

* Explore: fixes formatting

* Explore: updates grafana-data datasource types - replaces strings with explore mode enum

* Explore: updates loki explore query field props to take ReactNode

* Explore: updates the way we calculate loki query lines limit to fall back to 0 lines on negative or invalid input instead of datasource maxLines

* Explore: updates result processor get logs result method to avoid counting invalid/negative line limits

* Explore: updates loki result transformer to process only an appropriate slice of a result instead of an entire one

* Explore: adds a method for query limit preprocessing/mapping

* Explore: updates loki datasource run range query with fallback method to use options.maxDataPoints in dashboards

* Explore: removes unnecessary maxlineslimt from getLogsResult in resultProcessor

* Explore: moves line limit to metadata

* Explore: adds an ability to specify input type of extra field

* Explore: updates LokiExploreQueryEditor - adds an input type

* Explore: updates LokiExploreQueryEditor to run queries when maxLines is positive

* Explore: fixes failing import of ExploreMode

* Explore: fixes reducers test imports formatting

* Explore: updates Loki extra field with min value set to 0

* Explore: exports LokiExploreExtraFieldProps

* Explore: adds render test of LokiExploreQueryEditor

* Explore: adds LokiExploreQueryEditor snapshot

* Explore: updates LokiExploreQueryEditor onChangeQueryLimit method to prevent it from running when query input is empty - fixes cheatsheet display issue

* Explore: updates Loki editor snapshots

* Explore: fixes typo in test set name in LokiExploreQueryEditor

* Explore: adds a render test of LokiExploreExtraField

* Explore: fixes typo in LokiExploreQueryEditor

* Explore: updates LokiExploreQueryEditor snapshot due to timezone issues

* Explore: updates LokiExploreExtraField to export both functional component and a version using memo

* Explore: updates LokiExploreQueryEditor to export both functional component and memoized function

* Explore: updates LokiExploreQueryEditor - removes unnecessary react fragment

* Explore: updates LokiExploreQueryEditor snapshot

* Explore: adds LokiExploreQueryEditor tests for different explore mode cases

* Explore: fixes Loki datasource and result transformer

* Explore: updates LokiExploreQueryEditor snapshot

* Explore: updates LokiExploreQueryEditor tests and test setup

* Explore: updates LokiExploreQueryEditor - refactors component

* Explore: updates LokiExploreQueryEditor to use default import from LokiExploreExtraField

* Explore: updates LokiExploreQueryEditor snapshot

* Explore: fixes formatting

* Explore: updates LokiExploreQueryEditor max lines change

* Explore: updates LokiExploreQueryEditor tests checking ExtraFieldElement

* Explore: adds mock loki datasource to LokiExploreQueryEditor

* Explore: updates LokiExploreQueryEditor test mock - adds language provider

* Explore: updates LokiExploreQueryEditor snapshot

* Explore: updates Loki ResultTransformer to filter out rows on limit - logic to be moved into a component with new form styles

* Explore: updates LokiExploreQueryEditor tests

packages/grafana-data/src/types/datasource.ts

@@ -312,6 +312,11 @@ export enum DataSourceStatus {
   Disconnected,
 }
 
+export enum ExploreMode {
+  Logs = 'Logs',
+  Metrics = 'Metrics',
+}
+
 export interface ExploreQueryFieldProps<
   DSType extends DataSourceApi<TQuery, TOptions>,
   TQuery extends DataQuery = DataQuery,
@@ -320,11 +325,12 @@ export interface ExploreQueryFieldProps<
   history: any[];
   onBlur?: () => void;
   absoluteRange?: AbsoluteTimeRange;
+  exploreMode?: ExploreMode;
 }
 
 export interface ExploreStartPageProps {
   datasource?: DataSourceApi;
-  exploreMode: 'Logs' | 'Metrics';
+  exploreMode: ExploreMode;
   onClickExample: (query: DataQuery) => void;
 }
 
@@ -384,6 +390,11 @@ export interface DataQuery {
   datasource?: string | null;
 
   metric?: any;
+
+  /**
+   * For limiting result lines.
+   */
+  maxLines?: number;
 }
 
 export interface DataQueryError {
@@ -414,7 +425,7 @@ export interface DataQueryRequest<TQuery extends DataQuery = DataQuery> {
   app: CoreApp | string;
 
   cacheTimeout?: string;
-  exploreMode?: 'Logs' | 'Metrics';
+  exploreMode?: ExploreMode;
   rangeRaw?: RawTimeRange;
   timeInfo?: string; // The query time description (blue text in the upper right)