Ensured use of IsConvertible property in SetValue()

As this value is now cached as a local property, that should be called.

Author: JeremyCaney

OnTopic/Internal/Reflection/MemberAccessor.cs

@@ -109,9 +109,8 @@ internal bool IsSettable(Type? sourceType = null, bool allowConversion = false)
         return true;
       }
       if (allowConversion) {
-        var isTargetCompatible  = AttributeValueConverter.IsConvertible(Type);
-        var isSourceCompatible  = sourceType is null || AttributeValueConverter.IsConvertible(sourceType);
-        return isTargetCompatible && isSourceCompatible;
+        var isSourceConvertible  = sourceType is null || AttributeValueConverter.IsConvertible(sourceType);
+        return IsConvertible && isSourceConvertible;
       }
       return false;
     }