Add debug_group to render graph

[IceSentry]

Objective

• Debugging an application with multiple cameras can be really annoying because it's hard to know at a glance which pass is associated with which camera.
• wgpu exposes a feature to set debug_group that will add labels around groups of passes and draw commands

Solution

• Expose the debug_group feature to the render graph.
  • Each sub graph can now specify a debug group
• Add a new debug group label to each camera with the camera order and entity id
• I also added the new debug_group to the tracy span so you can more easily see which span is associated with which camera

Testing

• I tested the 3d_scene and split_screen examples

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Showcase

Here's what it looked like before

Here's what the split_screen example looks like inside nvidia nsight with the new debug group labels. You can clearly see each camera clearly identified.