Extract SwipeAnimation out of SwipeTransition

This CL is very similar to ag/28575909: it extracts a SwipeAnimation
class that contain most of the logic needed for swipe transitions. This
will be used to implement swipe transition that can animate overlays in
& out.

This is a pure refactoring that does not add any feature.

Bug: 353679003
Test: atest DraggableHandlerTest
Flag: com.android.systemui.scene_container
Change-Id: I65511c8354ff14b431fd34abae30b666ea99d514