Add more gesture recognizer sample pages to ControlCatalog

[jsuarezruiz]

What does the pull request do?

Restructures the existing GesturePage in ControlCatalog from a single monolithic page into a navigable gallery with dedicated sample pages for each gesture type, and adds a new swipe gesture demo.

What is the current behavior?

The gesture sample page uses a TabControl with all gesture demos (pull, pinch/zoom, pinch/rotation) inlined in a single page. There is no swipe gesture demo.

What is the updated/expected behavior with this PR?

The GesturePage is now a NavigationPage gallery that links to four dedicated sample pages:

• Pull Gesture (Touch / Pen): drag from colored border zones, ball tracks delta and springs back on release
• Pinch / Zoom (Multi Touch): pinch to scale an image via composition visuals, scroll to pan when zoomed
• Pinch / Rotation (Multi Touch): pinch to rotate a rectangle, angle drives a RotateTransform
• Swipe Gesture (Touch / Pen / Mouse): new demo with configurable direction, threshold, and mouse support; shows live delta, velocity, and direction

Checklist

• Added unit tests (if possible)?
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Breaking changes

None

Obsoletions / Deprecations

None

[avaloniaui-bot]

You can test this PR using the following package version. 12.0.999-cibuild0064009-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[MrJul]

More samples :)
LGTM!