Verify Views files against decompiled, extract embedded types

Fixed files:
- SkiaImageButton.cs: Added SVG support with multi-path search
- SkiaNavigationPage.cs: Added LinuxApplication.IsGtkMode check
- SkiaRefreshView.cs: Added ICommand support (Command, CommandParameter)
- SkiaTemplatedView.cs: Added missing using statements

Extracted embedded types to separate files (matching decompiled pattern):
- From SkiaMenuBar.cs: MenuBarItem, MenuItem, SkiaMenuFlyout, MenuItemClickedEventArgs
- From SkiaNavigationPage.cs: NavigationEventArgs
- From SkiaTabbedPage.cs: TabItem
- From SkiaVisualStateManager.cs: SkiaVisualStateGroupList, SkiaVisualStateGroup, SkiaVisualState, SkiaVisualStateSetter
- From SkiaSwipeView.cs: SwipeItem, SwipeStartedEventArgs, SwipeEndedEventArgs
- From SkiaFlyoutPage.cs: FlyoutLayoutBehavior (already separate)
- From SkiaIndicatorView.cs: IndicatorShape (already separate)
- From SkiaBorder.cs: SkiaFrame
- From SkiaCarouselView.cs: PositionChangedEventArgs
- From SkiaCollectionView.cs: SkiaSelectionMode, ItemsLayoutOrientation
- From SkiaContentPresenter.cs: LayoutAlignment

Verified matching decompiled:
- SkiaContextMenu.cs, SkiaFlexLayout.cs, SkiaGraphicsView.cs

Build: 0 errors

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Interop/XButtonEvent.cs

@@ -0,0 +1,23 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.Maui.Platform.Linux.Interop;
+
+public struct XButtonEvent
+{
+    public int Type;
+    public ulong Serial;
+    public int SendEvent;
+    public IntPtr Display;
+    public IntPtr Window;
+    public IntPtr Root;
+    public IntPtr Subwindow;
+    public ulong Time;
+    public int X;
+    public int Y;
+    public int XRoot;
+    public int YRoot;
+    public uint State;
+    public uint Button;
+    public int SameScreen;
+}