Add scenario benchmarks comparing BVal and Hibernate Validator

ScenarioBenchmark runs each scenario against both providers, selected by a
JMH parameter, and checks the expected violation counts once per trial:
mixed valid/invalid beans, explicit groups, validateProperty/Value,
parameter and return value validation, cascading into large collections
and cycles, container element constraints, deep graphs, beans with many
built-in constraints (valid and fully invalid), composed and class-level
constraints, and EL message expressions.

Also run the JMH annotation processor explicitly, as JDK 23+ no longer
does so implicitly, and register Tomcat's ExpressionFactory ahead of the
bval-jsr test fixture that re-resolves its delegate on every call.

Both benchmark classes default to 2 forks of 3 warmup and 5 measurement
iterations of 1 s, so that a plain run takes minutes rather than hours.