Prior to this commit, test AOT processing failed if a feature name for
generated class names was used for more than one ApplicationContext.
For example, when generating code for org.example.MessageService with a
"Management" feature name, the "BeanDefinitions" class was named as
follows (without a uniquely identifying TestContext###_ feature name
prefix).
org/example/MessageService__ManagementBeanDefinitions.java
When another attempt was made to generate code for the MessageService
using the same "Management" feature name, a FileAlreadyExistsException
was thrown denoting that the class/file name was already in use.
To avoid such naming collisions, this commit introduces a
TestContextGenerationContext which provides a custom implementation of
withName(String) that prepends an existing feature name (if present) to
a new feature name, thereby treating any existing feature name as a
prefix to a new, nested feature name.
Consequently, code generation for the above example now results in
unique class/file names like the following (which retain the uniquely
identifying TestContext###_ prefixes).
org/example/MessageService__TestContext002_ManagementBeanDefinitions.java
org/example/MessageService__TestContext003_ManagementBeanDefinitions.java
Closes gh-30861
f5db8bd1e8