[PR1] Introduced batch versions of ray_fire() and point_in_volume() with GPRT backend

[Waqar-ukaea]

Summary

This PR adds core XDG support for batched GPRT ray queries, enabling both ray_fire() and point_in_volume() to run over many rays efficiently.

With this PR there are now two query paths to GPRT ray tracing:

• Scalar query (single ray) — primarily for debugging / comparison (launching a full RT pipeline for one ray is expensive).
• Batch query (host → device staging) — accepts arrays of origins/directions and launches the RT pipeline once for the entire batch. Single Volume

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Public API Changes

GPRTRayTracer (new / overridden)

Point-in-volume

• point_in_volume(...) — batched PIV over points (optional directions and exclude list).

Ray fire

• ray_fire(...) — batched ray fire over origins/directions (with distance limit, orientation, optional exclude list).

Buffer / workflow plumbing

• check_rayhit_buffer_capacity(...) — ensure device buffers can accommodate N rays.

GPRT backend accessors

• context() — access the underlying GPRT context. Currently required since GPRT does not implement VK_EXTERNAL_MEMORY as of yet. So to mock an external application, I use "external" compute shaders attached to the same underlying GPRTContext.

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RayTracer interface (new virtuals)

Adds virtual entry points for batched and prepared workflows:

• point_in_volume(...)
• ray_fire(...)
• check_rayhit_buffer_capacity(...)

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XDG API (new overloads / helpers)

Batched launch

• ray_fire(...) — volume-level overload for batched ray fire.

Also included are a set of tests for the new batch API versions of the two methods.