Add attribute support for FactoryBean bean definitions

[philwebb]

Spring Boot currently supports the use of a BeanDefinition attribute for defining the ResolableType that a FactoryBean will ultimately return.

This is used in Spring Boot itself and also Spring Data so that we can obtain sensible results without creating the FactoryBean. For #23056, we will need a say to support this in the Spring Framework call so that methods such as getBeanNamesForType work correctly.