This PR implements debug groups in the render graph. Each node contains
a reference to the debug group they belong to. During scheduling the
nodes can be reordered and the correct debug group needs to be
activated.
This is done by keeping track of the current debug group. When a
different debug group is needed, the needed ends/begins are added
to the command buffer.
This mechanism also cleans up debug groups that are not used at all
as they don't have any nodes associated to it.
Pull Request: https://projects.blender.org/blender/blender/pulls/122054
488e74a209