Tracing: add way to configure trace to logs start and end time (#34995)

* Tracing: add way to configure trace to logs start and end time

* Use the span's time by default

* Update docs

* Update time inputs to use strings instead of number

* Support negative values as well

* Add info about using negative value

* Don't round up Loki range

* Update docs/sources/datasources/jaeger.md

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

* Wording for doc

* Round adjusted start and end time

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

packages/grafana-data/src/datetime/rangeutil.test.ts

@@ -41,6 +41,14 @@ describe('Range Utils', () => {
       expect(() => rangeUtil.describeInterval('123xyz')).toThrow();
       expect(() => rangeUtil.describeInterval('xyz')).toThrow();
     });
+
+    it('should be able to parse negative values as well', () => {
+      expect(rangeUtil.describeInterval('-50ms')).toEqual({
+        sec: 0.001,
+        type: 'ms',
+        count: -50,
+      });
+    });
   });
 
   describe('relativeToTimeRange', () => {

packages/grafana-data/src/datetime/rangeutil.ts

@@ -276,7 +276,7 @@ export function calculateInterval(range: TimeRange, resolution: number, lowLimit
   };
 }
 
-const interval_regex = /(\d+(?:\.\d+)?)(ms|[Mwdhmsy])/;
+const interval_regex = /(-?\d+(?:\.\d+)?)(ms|[Mwdhmsy])/;
 // histogram & trends
 const intervals_in_seconds = {
   y: 31536000,