add: basic debug overlay

src/Cafe/HW/Latte/Renderer/Metal/MetalPerformanceMonitor.h

@@ -0,0 +1,18 @@
+#pragma once
+
+class MetalPerformanceMonitor
+{
+public:
+    size_t m_bufferAllocatorMemory = 0;
+
+    // Per frame data
+    uint32 m_renderPasses = 0;
+
+    MetalPerformanceMonitor() = default;
+    ~MetalPerformanceMonitor() = default;
+
+    void ResetPerFrameData()
+    {
+        m_renderPasses = 0;
+    }
+};