Deprecate QCamera::FocusModeAutoNear and Far

We cannot implement QCamera::FocusModeAutoNear and AutoFar on Android, as there are no settings that are similar to these in the Android Camera2 API. These types only have iOS equivalents in AVFoundation. This is not ideal, since we want to have unified APIs that we can reliably implement on multiple platforms, especially across mobile platforms.

It seems there is some customer demand for this kind of functionality, such as when scanning QR codes. The best option that we can implement is the QCamera::focusPoint functionality. I believe this will require us to make a separate QCamera::FocusModeCustomFocusPoint enumerator, and will require some clarifications on the semantics of how it works.