[Feat] (MG_Backend/DirectVulkan): native GPU indirect draws + draw parameters

- Enable multiDrawIndirect and shaderDrawParameters device features when
  supported (the latter via VkPhysicalDeviceShaderDrawParametersFeatures on
  Vulkan 1.1+), so DrawIndex/BaseInstance SPIR-V builtins are valid and
  vkCmdDrawIndexedIndirect(Count) may draw more than one command.
- Plain glMultiDrawElementsIndirect no longer requires a GL_PARAMETER_BUFFER
  (it previously drew nothing for the standard Flywheel call); it now issues
  a native vkCmdDrawIndexedIndirect, with a per-command loop fallback when
  the multiDrawIndirect feature is unavailable.
- glDrawElementsIndirect / glDrawArraysIndirect / glMultiDrawArraysIndirect
  read the live GPU buffer via native indirect draws instead of the CPU
  shadow (which cannot see compute-written commands); the CPU path remains
  only for client-memory commands.
- Advertise the same five extensions as DirectGLES for Flywheel's
  capability probe.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.h

@@ -156,6 +156,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         void DrawArrays(const DrawCmd& payload);
         void DrawElements(const DrawIndexedCmd& payload);
         void MultiDrawElements(const MultiDrawIndexedCmd& payloads);
+        void MultiDrawElementsIndirect(GLenum mode, GLenum type, const void* indirect, GLsizei drawcount,
+                                       GLsizei stride);
+        void MultiDrawArraysIndirect(GLenum mode, const void* indirect, GLsizei drawcount, GLsizei stride);
         void MultiDrawElementsIndirectCount(GLenum mode, GLenum type, const void* indirect, GLintptr drawcount,
                                             GLsizei maxdrawcount, GLsizei stride);
         void Present();
@@ -229,6 +232,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         Bool m_drawIndirectCountExtensionEnabled = false;
         Bool m_indexTypeUint8ExtensionEnabled = false;
         Bool m_logicOpFeatureEnabled = false;
+        Bool m_multiDrawIndirectFeatureEnabled = false;
+        Bool m_shaderDrawParametersExtensionEnabled = false;
+        Bool m_shaderDrawParametersFeatureEnabled = false;
         using PFNDrawIndexedIndirectCountFunc = void(VKAPI_PTR*)(VkCommandBuffer commandBuffer, VkBuffer buffer,
                                                                  VkDeviceSize offset, VkBuffer countBuffer,
                                                                  VkDeviceSize countBufferOffset, Uint32 maxDrawCount,