perf-test: enhance the profiling measurement

[hermet]

The current performance stats display the current value along with the minimum and maximum values during measurement. However, the minimum and maximum values are highly unpredictable and do not provide meaningful insights into the overall condition. Instead, presenting the accumulated values as an average would be more effective and informative.

For example in case of FPS:

accumulatedFPS = 0;  //FPS in accumulated value.
...
if (first frame) accumulatedFPS += currentFPS;
else accumulatedFPS = (accumulatedFPS + currentFps) / 2  //update it every frame.

Eventually, we can display the accumulatedFPS in the format: current fps (accumulated fps), instead of the current format: current fps (min fps- max fps). This approach can also be applied to memory usage and other performance stats.