BeanInstanceExecutableSupplier does not detect factory method when target type is set to the type it produces

[snicoll]

Consider the following example:

public MyFactory {

    public static MyBean createBean(MyParam) {
    }
}

And a BeanDefinition where the target type is set to MyBean with a beanClass set to MyFactory. The algorithm currently uses the target type as the primary candidate, falling back to the beanClass if necessary.

In the case of a factory method, this is wrong and we should improve the logic to consider the beanClass use case.