Add Global Bias and RMSE Plots for Significant Wave Height (Hs) and Wind Speed

[mingchen-NOAA]

Add a new script to ww3tools that produces global Bias and RMSE plots for both significant wave height (Hs) and wind speed. This enhancement will provide a powerful and consolidated diagnostic for global wave model evaluations.

[JessicaMeixner-NOAA]

@mingchen-NOAA - Did an issue come up with adding this to the repo?

[mingchen-NOAA]

@mingchen-NOAA - Did an issue come up with adding this to the repo?

No issue. I will submit PR shortly.