Improve vertex selection and handling, add vertical menubar

[donkeyProgramming]

PR Classification

New feature and UI/UX improvement for 3D editor selection and visualization.

PR Summary

This PR modernizes the vertex and edge selection system in the 3D editor, introducing Blender-style rendering, improved picking accuracy, and a new sidebar UI. It also adds scene statistics and robust unit tests for selection logic.

• VertexInstanceMesh.cs, VertexPointShader.fx: Replaced cube-based vertex rendering with camera-facing circular points using a new shader.
• EdgeQuadInstanceMesh.cs, EdgeQuadShader.fx: Added thick, anti-aliased edge rendering with color based on selection weights.
• IntersectionMath.cs: Updated selection logic to use screen-space proximity for vertex picking and added edge intersection helpers.
• KitbasherView.xaml, MenuBarViewModel.cs: Introduced a vertical sidebar for selection/gizmo tools and reorganized toolbar buttons.
• SceneInformationComponent.cs: Added real-time scene and selection statistics display in the viewport.