Update KeyboardObserver

[robmaceachern]

This updates the KeyboardObserver to match the more recent implementation we use elsewhere.

Changes include:

• Support for the iOS 16.1+ changes related to the screen coordinate space. This can impact reported values when the app isn't full screen in Split View, Slide Over, and Stage Manager.
• The delegate has been changed to report the UIView.AnimationCurve instead of UIView.AnimationOptions
• Various formatting changes to match other implementations.
• ListView changes:
  • We now use a UIViewPropertyAnimator instead of UIView.animate when responding to keyboard notifications.
  • The KeyboardFrameWillChangeCallback now receives the UIView.AnimationCurve instead of UIView.AnimationOptions

Note: This implementation

Checklist

Please do the following before merging:

• [x] Ensure any public-facing changes are reflected in the changelog. Include them in the Main section.

[robmaceachern]

@kyleve The notification screen handling was updated in https://github.com/square/Listable/pull/499/commits/27d578d368f8e02eed3f04a68ea2a923a3f5707e to match the revised Market implementation (https://github.com/squareup/market/pull/6826).