Seek::get() should return a struct for readibility instead of a tuple

I just found myself writing this in a test:

match ev.view() {
    gst::EventView::Seek(seek) => {
        let start = seek.get().3;

I don't think someone using GStreamer should have to count fields to figure out which one is which.

Is there a reason .get() returns an unnamed tuple instead of struct with named fields?

Should we add a version that returns a struct with named fields?