Redesign touch input system

[bastianeicher]

This project contains incomplete code for adding touch support to WinForms projects. This code lives in:

• src/Common.WinForms/Controls/ITouchControl.cs
• src/Common.WinForms/Controls/TouchForm.cs
• src/Common.WinForms/Controls/TouchPanel.cs
• src/Common.WinForms/Native/WinFormsUtils.Touch.cs

Currently it tries to represent raw touch events. We should redesign this to expose the higher-level Windows Touch Gestures instead.

Replace the delegates in ITouchControl and its implementations from TouchDown, TouchUp and TouchMove with Tap, Pan, Zoom, etc..

Look at https://github.com/microsoft/Windows-classic-samples/blob/main/Samples/Win7Samples/Touch/MTGestures/CS/MTGestures.cs for details how the native interop works.
In our own implementation we want to keep all the native code nicely isolated in WinFormsUtils.Touch.cs.