Explore: Support user timezone (#16469)

Explore now uses the timezone of the user to decide if local browser 
time or UTC should be used. 
- Now uses TimeRange instead of RawTimeRange in explore item
state tree and only parsing actual time in a few action
handlers.
- Time picker should now properly handle moving back/forward and
apply time range when both utc and non utc time zone.
- URL range representation is changed from YYYY-MM-DD HH:mm:ss
to epoch ms.
- Now uses AbsoluteTimeRange in graph component instead of moment.
- Makes a copy of the time range passed to timeSrv to make sure immutability
of explore time range when for example elasticsearch test datasources uses
timeSrv and sets a time range of last 1 min.
- Various refactorings and cleanup.

Closes #12812

public/app/features/explore/LogsContainer.tsx

@@ -1,7 +1,7 @@
 import React, { PureComponent } from 'react';
 import { hot } from 'react-hot-loader';
 import { connect } from 'react-redux';
-import { RawTimeRange, TimeRange, LogLevel } from '@grafana/ui';
+import { RawTimeRange, TimeRange, LogLevel, TimeZone, AbsoluteTimeRange } from '@grafana/ui';
 
 import { ExploreId, ExploreItemState } from 'app/types/explore';
 import { LogsModel, LogsDedupStrategy } from 'app/core/logs_model';
@@ -12,6 +12,7 @@ import Logs from './Logs';
 import Panel from './Panel';
 import { toggleLogLevelAction } from 'app/features/explore/state/actionTypes';
 import { deduplicatedLogsSelector, exploreItemUIStateSelector } from 'app/features/explore/state/selectors';
+import { getTimeZone } from '../profile/state/selectors';
 
 interface LogsContainerProps {
   exploreId: ExploreId;
@@ -19,11 +20,12 @@ interface LogsContainerProps {
   logsHighlighterExpressions?: string[];
   logsResult?: LogsModel;
   dedupedResult?: LogsModel;
-  onChangeTime: (range: TimeRange) => void;
+  onChangeTime: (range: AbsoluteTimeRange) => void;
   onClickLabel: (key: string, value: string) => void;
   onStartScanning: () => void;
   onStopScanning: () => void;
-  range: RawTimeRange;
+  range: TimeRange;
+  timeZone: TimeZone;
   scanning?: boolean;
   scanRange?: RawTimeRange;
   showingLogs: boolean;
@@ -64,6 +66,7 @@ export class LogsContainer extends PureComponent<LogsContainerProps> {
       onStartScanning,
       onStopScanning,
       range,
+      timeZone,
       showingLogs,
       scanning,
       scanRange,
@@ -88,6 +91,7 @@ export class LogsContainer extends PureComponent<LogsContainerProps> {
           onDedupStrategyChange={this.handleDedupStrategyChange}
           onToggleLogLevel={this.hangleToggleLogLevel}
           range={range}
+          timeZone={timeZone}
           scanning={scanning}
           scanRange={scanRange}
           width={width}
@@ -106,6 +110,7 @@ function mapStateToProps(state: StoreState, { exploreId }) {
   const { showingLogs, dedupStrategy } = exploreItemUIStateSelector(item);
   const hiddenLogLevels = new Set(item.hiddenLogLevels);
   const dedupedResult = deduplicatedLogsSelector(item);
+  const timeZone = getTimeZone(state.user);
 
   return {
     loading,
@@ -115,6 +120,7 @@ function mapStateToProps(state: StoreState, { exploreId }) {
     scanRange,
     showingLogs,
     range,
+    timeZone,
     dedupStrategy,
     hiddenLogLevels,
     dedupedResult,