Geometry Nodes: Avoid corner domain for Blur Attribute viewing

Face Corner is not supported.
In case prefer domain is used, face corner shouldn't be proposed.
This will make the viewer node preview the values on the point
domain instead in the viewport.

Pull Request: https://projects.blender.org/blender/blender/pulls/113905

source/blender/nodes/geometry/nodes/node_geo_blur_attribute.cc

@@ -485,7 +485,12 @@ class BlurAttributeFieldInput final : public bke::GeometryFieldInput {
 
   std::optional<eAttrDomain> preferred_domain(const GeometryComponent &component) const override
   {
-    return bke::try_detect_field_domain(component, value_field_);
+    const std::optional<eAttrDomain> domain = bke::try_detect_field_domain(component,
+                                                                           value_field_);
+    if (domain.has_value() && *domain == ATTR_DOMAIN_CORNER) {
+      return ATTR_DOMAIN_POINT;
+    }
+    return domain;
   }
 };