[Optimaization] (MG_Backend/DirectVulkan): optimize perf

- Properly reuse descriptor sets rather than always allocating
- Add program lookup cache

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.h

@@ -172,6 +172,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         static VkShaderStageFlagBits ToVkStage(ShaderStage stage);
 
     private:
+        struct ProgramLookupCache {
+            const MG_State::GLState::ProgramObject* program = nullptr;
+            Uint32 backendStateVersion = 0;
+            CompileOptionFlags flags{};
+            HashType hash = 0;
+        };
+
         static TextureTarget UniformTypeToTextureTarget(GLenum glType);
         void ReflectVertexInputs(const Vector<SharedPtr<MG_State::GLState::ShaderObject>>& shaders,
                      const Vector<Vector<Uint>>& spirv,
@@ -186,6 +193,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         Uint32 m_maxBindings = 0;
         UnorderedMap<HashType, VkProgramObject> m_cache;
         const VulkanRendererConfig& m_config;
+        mutable ProgramLookupCache m_lastLookup;
         static inline XXH64_state_t* m_hashState = XXH64_createState();
     };
 } // namespace MobileGL::MG_Backend::DirectVulkan