Allow excluding certain violations from being reported

[pboos]

Allow excluding certain violations using a custom ViolationExclusions bean.

For example:

@Component
public class ViolationExclusionsImpl implements ViolationExclusions {
    @Override
    public boolean isExcluded(OpenApiViolation violation) {
        return violation.getDirection().equals(Direction.REQUEST)
            && violation.getMessage().equals("[Path '/name'] Instance type (integer) does not match any allowed primitive type (allowed: [\"string\"])");
    }
}