[Fix] (MG_Backend/DirectVulkan): support Voxy rendering

Implemented:

- Advertise Voxy-required DirectVulkan extensions without raising the reported OpenGL version.

- Add DirectVulkan compute, indirect draw count, DSA, readback, and buffer state paths needed by Voxy.

Fixed:

- Enable Vulkan shaderInt64 and drawIndirectFirstInstance so Voxy baseInstance-driven LOD draws address the correct section data.

- Fix DirectVulkan synchronization, framebuffer, texture readback, and shader interface handling used by Voxy and Minecraft screenshots.

Tests:

- Add MG_Test coverage for DirectVulkan extension advertising, DSA buffer/texture/framebuffer/vertex-array behavior, persistent mapped readback, and shader/program paths.

MobileGL/MG_State/GLState/BufferState/BufferObject.h

@@ -25,6 +25,7 @@ namespace MobileGL {
         AtomicCounter,
         DispatchIndirect,
         DrawIndirect,
+        Parameter,
         ShaderStorage,
         BufferTargetCount,
         Unknown = -1