Switch from BGL to GPU module

[Durman]

Problem statement

BGL Deprecation BGL is a direct wrapper around OpenGL calls. The BGL module is deprecated for and since Blender 3.4 has been replaced with the gpu module. From this release it will not work when using the Metal backend. Add-ons and scripts that uses the bgl module are warned about the deprecation and should use the gpu module in stead.

https://wiki.blender.org/wiki/Reference/Release_Notes/3.5/Python_API

Nodes require changes:

• [ ] Viewer Draw
• [ ] Stethoscope MK2
• [ ] Matrix View
• [ ] Viewer Index
• [ ] Viewer 2D
• [ ] Viewer Draw Curve
• [ ] Viewer Draw Surface
• [ ] Texture Viewer
• [ ] Texture Viewer Lite
• [ ] SvWaveformViewer
• [ ] Console Node
• [ ] Solid Viewer (did not test)
• [ ] Easing 0..1