Plugins: Introduce new Flame graph panel (#56376)

* Flamegraph

* Updated flame graph width/height values

* Fix top table rendering issue

* Add feature toggle for flamegraph in explore

* Update tests

* Hide flamegraph from dash panel viz list if feature toggle not enabled

* Show table if no flameGraphFrames

* Add flame graph to testdata ds

* Minor improvement

pkg/tsdb/testdatasource/scenarios.go

@@ -39,6 +39,7 @@ const (
 	serverError500Query               queryType = "server_error_500"
 	logsQuery                         queryType = "logs"
 	nodeGraphQuery                    queryType = "node_graph"
+	flameGraphQuery                   queryType = "flame_graph"
 	rawFrameQuery                     queryType = "raw_frame"
 	csvFileQueryType                  queryType = "csv_file"
 	csvContentQueryType               queryType = "csv_content"
@@ -195,6 +196,11 @@ Timestamps will line up evenly on timeStepSeconds (For example, 60 seconds means
 		Name: "Node Graph",
 	})
 
+	s.registerScenario(&Scenario{
+		ID:   string(flameGraphQuery),
+		Name: "Flame Graph",
+	})
+
 	s.registerScenario(&Scenario{
 		ID:   string(rawFrameQuery),
 		Name: "Raw Frames",