Validator for vlt:PackageDefinition serialization (META-INF/vault/definition)

The serialized node at META-INF/vault/definition should not contain properties originally coming from package properties. Those are anyways overridden during unwrap (https://github.com/apache/jackrabbit-filevault/blob/39b4463904719a423a3ebe000b049b0653557591/vault-core/src/main/java/org/apache/jackrabbit/vault/packaging/impl/JcrPackageDefinitionImpl.java#L239). Only that information which is not redundant should be allowed in that serialized node.

Note: Packages created from CRX Package Manager contain redundant metadata as the whole node with type vlt:PackageDefinition is serialized, without taking into consideration whether the info is natively stored somewhere else, so most probably this validation should be limited to packages being created with the Maven plugin.