Use @testdox annotation as the label for test classes and methods

[chiefmyron]

PHPUnit allows the use of a @testdox annotation to allow for an alternative description of a test class and/or test methods within the class:
https://docs.phpunit.de/en/10.0/annotations.html#testdox

Add a new option to allow these alternative descriptions to be used as the display label for classes and tests within the Test Explorer tree. If the option is enabled but no annotation is found, then the Test Explorer should fallback to using the class or method name.