[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_Impl/GLImpl/RenderState/GL_RenderState.cpp

@@ -168,6 +168,21 @@ namespace MobileGL::MG_Impl::GLImpl {
         MG_State::pGLContext->SetFrontFaceMode(frontFaceMode);
     }
 
+    void ProvokingVertex_State(GLenum mode) {
+        ProvokingVertexMode provokingVertexMode = MG_Util::ConvertGLEnumToProvokingVertexMode(mode);
+        if (provokingVertexMode == ProvokingVertexMode::Unknown) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidEnum,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", "ProvokingVertex_State",
+                                             "Provoking vertex mode enum " +
+                                                 MG_Util::ConvertProvokingVertexModeToString(provokingVertexMode) +
+                                                 "(" + MG_Util::ConvertGLEnumToString(mode) + ") is not supported."));
+            return;
+        }
+
+        MG_State::pGLContext->SetProvokingVertexMode(provokingVertexMode);
+    }
+
     void Enable_State(GLenum cap) {
         CapabilityInput capInput = MG_Util::ConvertGLEnumToCapabilityInput(cap);
         if (capInput == CapabilityInput::Unknown) {
@@ -499,6 +514,10 @@ namespace MobileGL::MG_Impl::GLImpl {
         FrontFace_State(mode);
     }
 
+    void ProvokingVertex(GLenum mode) {
+        ProvokingVertex_State(mode);
+    }
+
     void Enable(GLenum cap) {
         Enable_State(cap);
     }