Material 3 Adaptive 1.2.0 is stable

Material 3 Adaptive 1.2.0 is now stable, enhancing adaptive UI development. This release adds support for new large and extra-large window size breakpoints. These new breakpoints are enabled by setting `supportLargeAndXLargeWidth` to true in `currentWindowAdaptiveInfo()`. The library also introduces two new adaptive strategies: reflow and levitate. The reflow strategy automatically rearranges panes based on window size and aspect ratio for optimal display. Panes can appear side-by-side or stacked vertically depending on available space. The levitate strategy allows content to be docked or float on top of other panes. Levitate offers customization for draggability, resizability, and background scrim. Both reflow and levitate strategies can be applied to ListDetailPaneScaffold and SupportingPaneScaffold. These strategies are configured within the Navigator constructor using the `adaptStrategies` parameter. Developers can explore these new features further on the Material website and GitHub.