Final refactoring: Removing GestureUiState

GestureUiState was supposed to be middle state between GestureState and TutorialActionState but in practice it ended up very similar to TutorialActionState and made states overly complicated.
Also meant that transformation stateful logic was kept in Composables - that logic is now moved to TouchpadTutorialScreenViewModel and tested in TouchpadTutorialScreenViewModelTest (formerly tested in StateTransitionsTest).

Now there's simply GestureState on domain side and TutorialActionState on UI side and ViewModel is transforming one into another.

Fixes: 384509663
Test: unit tests
Flag: com.android.systemui.shared.new_touchpad_gestures_tutorial
Change-Id: I088ee8a0f77b3595d695041ad23b72bfb30a20d0