Add Lane labels to scheduling profiler marks

This commit changes scheduling profiler marks from a format like '--schedule-render-1' to '--schedule-render-1-Sync' (where 1 is the numeric value of the Sync lane). This will enable the profiler itself to show more meaningful labels for updates and render work.

The commit also refactors and adds additional tests for the sceduling profiler package.

Author: Brian Vaughn

packages/react-devtools-scheduling-profiler/src/constants.js

@@ -11,5 +11,6 @@ export {
   COMFORTABLE_LINE_HEIGHT,
   COMPACT_LINE_HEIGHT,
 } from 'react-devtools-shared/src/constants.js';
+import {TotalLanes} from 'react-reconciler/src/ReactFiberLane.new';
 
-export const REACT_TOTAL_NUM_LANES = 31;
+export const REACT_TOTAL_NUM_LANES = TotalLanes;