Use ImGuiWindow from gen, support AddCallback

imgui/Dalamud.Bindings.ImGui/Custom/ImDrawCallbackEnum.cs

@@ -0,0 +1,15 @@
+namespace Dalamud.Bindings.ImGui;
+
+public enum ImDrawCallbackEnum
+{
+    Empty,
+
+    /// <summary>
+    /// Special Draw callback value to request renderer backend to reset the graphics/render state.
+    /// The renderer backend needs to handle this special value, otherwise it will crash trying to call a function at
+    /// this address. This is useful for example if you submitted callbacks which you know have altered the render
+    /// state, and you want it to be restored. It is not done by default because they are many perfectly useful way of
+    /// altering render state for imgui contents (e.g. changing shader/blending settings before an Image call).
+    /// </summary>
+    ResetRenderState = -1,
+}