Prior to this commit, a @BeanOverride (such as @TestBean) for a
specific target bean which was declared in a superclass always took
precedence over a bean override for the same target bean in a subclass,
thereby rendering the bean override configuration in the subclass
useless. In other words, there was no way for a test class to override
a bean override declared in a superclass.
To address that, this commit switches from direct use of
ReflectionUtils.doWithFields() to a custom search algorithm that
traverses the class hierarchy using tail recursion for processing
@BeanOverride fields (delegating now to
ReflectionUtils.doWithLocalFields() in order to continue to benefit
from the caching of declared fields in ReflectionUtils).
Closes gh-34194
ef4f1f0a71