Eliminate the need to adjust scroll position

[wtmoose]

It may be possible to adjust the safe area padding instead of the scroll position, which would significantly simplify the API. However, this requires frame-by-frame tracking of scroll view parameters. The SwiftUI method for tracking content offset doesn't seem to provide that frame-by-frame accuracy in my experimentation. Specifically, if one adjusts the safe area padding of a scroll view, there should be an automatic equal and opposite adjustment to the content offset to maintain spatial consistent of the effective scroll position. However, using the SwiftUI technique for tracking the content offset, those adjustments are not being observed in a consistent, predictable pattern, making it impossible to have the header fluidly track the scroll. However, by delving into UIKit, it may be to track these parameters accurately at every frame.