text: Title: Plotter screenshot scale has no effect
  Body: Hi Marco, 
  
  I was installing newest version (`'2023.4.4'`) of vedo through pip and noticed that my rendered images degraded in quality.
  I found that the `scale` parameter in `screenshot` function of plotter has no effect if `asarray=True`, ie if i get the following output
  ```
  >> plt.screenshot(asarray=True, scale=2).shape
  (1920, 1920, 3)
  >> plt.screenshot(asarray=True, scale=5).shape
  (1920, 1920, 3)
  ```
  When `asarray=False` in the function call and i specify a filename the scale parameter works just fine 👍 
  
  I downgraded vedo to version `'2023.4.3'` and there everything related to this bug works fine.