[Development] Proposal for UseSheet in QFileDialog option

[Yuë Liu]

Hello,

In QFileDialog documentation it says QFileDialog::DontUseSheet is no
longer supported and user should use QFileDialog::open() if they want
to use sheets, but for many simple application static methods are
enough and simpler, and when porting existing kde applications to
qfiledialog, modify existing exec() logic to open() logic is a lot of
work, it's easier to just use static methods but window modal is not
supported there. Can we re-enable the windowModal by default feature
or add an QFileDialog::UseSheet options so that when we want window
modal when using static method we can just apply the option?

Thanks,
Yue Liu