Adds two modes of GPU frame capture support for
enhanced debugging. GPU frame capture begin/end
allow instantaneous frame capture of all GPU commands
within the capture boundary.
GPU frame capture scopes allow several user-defined capture
regions which can wrap key parts of code. These scopes are
exposed to connected GPU tools allowing the user to manually
trigger a capture of a known scope at the desired time.
This is currently integrated with the Metal backend for
support with Xcode.
Related to #105591
Jason Fielder
Michael Parkin-White