Need an .Class method for Class in the Style<T> extension

[mdelgadov]

With Xaml styles and classes, we can compose flexible styles.

Nevertheless, we can't create classes with the Markup Style extension.

So, currently we need to do this:

Style s = Style().Add()... etc.

s.Class = "class";

etc.

Which is not elegant, takes the style out of the wrapper and feels incomplete.

I propose to create an extension method:

public Style Class(BindableProperty property, string className)
{
MauiStyle.Class = className;
return this
}
That fits nicely with the fluent notation.
If approved, I write the code, test it and present the PR....