Implement samples using ReticleVertexTool for UWP

[duffh]

Description

Added samples to UWP viewer:

• Create and edit geometries
• Snap geometry edits

Type of change

• Other enhancement

Platforms tested on

• UWP

Checklist

• Self-review of changes
• All changes work as expected on all affected platforms
• There are no warnings related to changes
• Code is commented and follows .NET conventions and standards
• Codemaid and XAML styler extensions have been run on every changed file
• No unrelated changes have been made to any other code or project files
• Screenshots are correct size and display in description tab (800 x 600 on Windows, MAUI mobile platforms use the MAUI Windows screenshot)