Hotkeys: Make time range permanent (#43802)

Typing `t a` in Explore or Dashboards will turn a relative time like "Last 1 hour"
into an absolute range to make the URL permanent, so that when sharing it others
will see the same data.

- registered `t a` in key service
- new `AbsoluteTimeEvent` dispatch via global event bus
- dashboard times handled in TimeSrv
- Explore times handled in Explore.tsx and Explore's time reducer

I could not find an easy way to combine time handling for Exlore and Dashboard in one place.

public/app/features/dashboard/services/TimeSrv.ts

@@ -14,7 +14,7 @@ import { getShiftedTimeRange, getZoomedTimeRange } from 'app/core/utils/timePick
 import { config } from 'app/core/config';
 import { getRefreshFromUrl } from '../utils/getRefreshFromUrl';
 import { locationService } from '@grafana/runtime';
-import { ShiftTimeEvent, ShiftTimeEventPayload, ZoomOutEvent } from '../../../types/events';
+import { AbsoluteTimeEvent, ShiftTimeEvent, ShiftTimeEventPayload, ZoomOutEvent } from '../../../types/events';
 import { contextSrv, ContextSrv } from 'app/core/services/context_srv';
 import appEvents from 'app/core/app_events';
 
@@ -41,6 +41,10 @@ export class TimeSrv {
       this.shiftTime(e.payload);
     });
 
+    appEvents.subscribe(AbsoluteTimeEvent, () => {
+      this.makeAbsoluteTime();
+    });
+
     document.addEventListener('visibilitychange', () => {
       if (this.autoRefreshBlocked && document.visibilityState === 'visible') {
         this.autoRefreshBlocked = false;
@@ -348,6 +352,16 @@ export class TimeSrv {
     });
   }
 
+  makeAbsoluteTime() {
+    const params = locationService.getSearch();
+    if (params.get('left')) {
+      return; // explore handles this;
+    }
+
+    const { from, to } = this.timeRange();
+    this.setTime({ from, to });
+  }
+
   // isRefreshOutsideThreshold function calculates the difference between last refresh and now
   // if the difference is outside 5% of the current set time range then the function will return true
   // if the difference is within 5% of the current set time range then the function will return false