feat(api): use uintptr_t instead of intptr_t for pointers (#265)

Image methods now accept the `long` type instead of `int`,
as they are expected to work with pointers as well.

imgui-binding/src/main/java/imgui/extension/imguifiledialog/ImGuiFileDialog.java

@@ -301,6 +301,6 @@ public final class ImGuiFileDialog {
      * @return user datas sent with Open Dialog/Modal
      */
     @BindingMethod
-    @ReturnValue(callPrefix = "(intptr_t)")
+    @ReturnValue(callPrefix = "(uintptr_t)")
     public static native long GetUserDatas();
 }