Make Top App Bar collapse on scroll

[ghusta]

See:

• https://github.com/material-components/material-components-android/blob/1.12.0/docs/components/TopAppBar.md#applying-scrolling-behavior-to-the-top-app-bar

Must use:

• app:liftOnScroll="true" (on AppBarLayout) -- ie. elevation
• app:liftOnScrollTargetViewId (on AppBarLayout, to the ListView)
• app:layout_scrollFlags="scroll|enterAlways" (on MaterialToolbar)
• androidx.core.view.ViewCompat#setNestedScrollingEnabled (in Activity#onCreate)

First do #473

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See also:

• https://m3.material.io/components/app-bars/specs#9975d8e5-f69e-48bd-865e-af3c8eeba1d3 (Scroll states)