Function file_ux__save_file_dialog 

pub unsafe extern "C" fn file_ux__save_file_dialog(
    proposed_filename_ptr: *const u8,
    proposed_filename_len: u32,
    data_ptr: *const u8,
    data_len: u32,
) -> ErrorCode

Lets the user save raw data to a file, popping up Save file dialog.

The proposed filename must include a file extension, this will be used to set up the save dialog filter.