LibWeb: Optimize CSS::StyleDeclaration for size

We can reduce the amount of padding the compiler adds in order to
ensure data alignment of member variables by ordering the types in
a struct by size in decending order.

Found By PVS-Studio: https://pvs-studio.com/en/docs/warnings/v802/

Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp

@@ -87,9 +87,9 @@ bool PropertyOwningCSSStyleDeclaration::set_property(PropertyID property_id, Str
     }
 
     m_properties.append(CSS::StyleProperty {
+        .important = false,
         .property_id = property_id,
         .value = new_value.release_nonnull(),
-        .important = false,
     });
     return true;
 }