Improve ChromeTraceUtil logging, allow filename to be specified.

Expose this ChromeTraceUtil  logging to C-API: start/statelogging and submitProfileTiming
pybullet.submitProfileTiming, and STATE_LOGGING_PROFILE_TIMINGS used in startStateLogging
added example for Python profileTiming.py and C++ b3RobotSimulatorClientAPI::submitProfileTiming

examples/ExampleBrowser/OpenGLExampleBrowser.cpp

@@ -260,7 +260,7 @@ void MyKeyboardCallback(int key, int state)
 
 			} else
 			{
-				b3ChromeUtilsStopTimingsAndWriteJsonFile();
+				b3ChromeUtilsStopTimingsAndWriteJsonFile("timings");
 			}
 	#endif //BT_NO_PROFILE
 		}