citra-qt: Improve shader debugger.

Now supports dumping the current shader and recognizes a larger number of output semantics.

src/citra_qt/debugger/graphics_vertex_shader.h

@@ -26,6 +26,8 @@ public:
 public slots:
     void OnUpdate();
 
+    void DumpShader();
+
 private:
     nihstro::ShaderInfo info;
 };