Prior to this commit, @TestBean factory methods had to be defined in
the test class, one of its superclasses, or in an implemented
interface. However, users may wish to define common factory methods in
external classes that can be shared easily across multiple test classes
simply by referencing an external method via a fully-qualified method
name.
To address that, this commit introduces support for referencing a
@TestBean factory method via its fully-qualified method name following
the syntax <fully-qualified class name>#<method name>.
Closes gh-33125
cc002875c4