Add Setting to change default "Forecast Model"

[SWDittmar]

In our area we find the GFS forecast model is most always the more accurate model.

I would like a setting added to default Windy to always startup with the GFS model.

This new setting should allow the user to set the default Forecast model to whichever model they prefer Windy to startup using

[idefix37]

@SWDittmar
See this relation post :
https://community.windy.com/topic/21895/set-gfs-model-as-default?_=1690827660895