QFileDialog::getOpenFileContent not honoring nameFilter

https://code.woboq.org/qt6/qtbase/src/widgets/dialogs/qfiledialog.cpp.html#_ZN11QFileDialog18getOpenFileContentERK7QStringRKSt8functionIFvS2_RK10QByteArrayEE

The first argument of QFileDialog::getOpenFileContent is nameFilter – in the Q_OS_WASM block, this is unused (with a comment about Qt and Web name filter string formats), but in the else block which is to be used on non-WASM platforms, it is being passed to a newly created QFileDialog via `selectNameFilter(nameFilter)` where no filters have yet to be set.

The fix is simple, which should simply be to swap in `setNameFilter(nameFilter);` instead at line 2337.

(Bonus points if nameFilter can be honored in the WASM section of the function!)