Introduce PropertyTransformation.Property

This CL introduces the notion of Property, which is used to understand
to which property a transformation is applied (instead of relying on
class hierarchy).

Bug: 376438969
Test: atest PlatformComposeSceneTransitionLayoutTests
Flag: com.android.systemui.scene_container
Change-Id: I9632d8892435eb9da1aba69315b67779279a3926