message: Query Browser: Stop polling when graph is hidden
  Stop polling the `query_range` Prometheus API endpoint when the graph is
  hidden.
diff: @@ -347,7 +347,9 @@ const QueryBrowser_: React.FC<QueryBrowserProps> = ({
  };
  const tick = () =>
  - Promise.all(_.map(queries, safeFetchQuery))
  + hideGraphs
  + ? undefined
  + : Promise.all(_.map(queries, safeFetchQuery))
  .then((responses: PrometheusResponse[]) => {
  const newResults = _.map(responses, 'data.result');
  const numDataPoints = _.sumBy(newResults, (r) => _.sumBy(r, 'values.length'));
  @@ -390,9 +392,9 @@ const QueryBrowser_: React.FC<QueryBrowserProps> = ({
  }
  });
  - // If an end time was set, stop polling since we are no longer displaying the latest data. Otherwise use a polling
  - // interval relative to the graph's timespan, but not less than 5s.
  - const delay = endTime ? null : Math.max(span / 120, 5000);
  + // Don't poll if an end time was set (because the latest data is not displayed) or if the graph is hidden. Otherwise
  + // use a polling interval relative to the graph's timespan, but not less than 5s.
  + const delay = endTime || hideGraphs ? null : Math.max(span / 120, 5000);
  usePoll(tick, delay, endTime, queries, samples, span);
  