Introduce `failOnError` flag in `TestContextAotGenerator`

[sbrannen]

Overview

When an error is encountered during AOT processing in TestContextAotGenerator, a DEBUG or WARN message is logged, and processing will continue.

This behavior is acceptable at build-time; however, such errors will be silently ignored within our own integration tests since we do not have a mechanism for checking the log output.

We should therefore introduce a mechanism to "fail on error" during test AOT processing.

NOTE: This feature is currently targeted for internal use only.

Related Issues

• Forbid loading of a test's ApplicationContext in AOT mode if AOT processing failed #29579
• Fail on error by default during test AOT processing #30977

Deliverables

• Introduce a failOnError flag in TestContextAotGenerator.
  • When set to true, any error encountered during AOT processing should result in an exception that fails the overall process. When set to false (the default), the previous behavior remains unchanged: a DEBUG or WARN message will be logged, and processing will continue.