Provide a configuration property for MethodValidationPostProcessor's adaptConstraintViolations

[Romster]

Spring documentation describes the way how to make an application raise MethodValidationException instead of ConstraintViolationException by declaring a bean

         @Bean
	public static MethodValidationPostProcessor validationPostProcessor() {
		MethodValidationPostProcessor processor = new MethodValidationPostProcessor();
		processor.setAdaptConstraintViolations(true);
		return processor;
	}

It would be great to have a dedicated property used in org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration#methodValidationPostProcessor to change this behaviour.

[wilkinsona]

Thanks for the suggestion, @Romster. I think this is a good idea.

Closing in favour of #43886. Thanks for the PR, @quaff.