Update Query tutorials to use SerializationContextInitializers

https://issues.jboss.org/browse/ISPN-10504 Deprecated the ProtostreamSerializationContextInitializer interface in favour of provding SerializationContextInitalizer implementations via the CacheManager's SerializationConfiguration. Therefore, we should update the tutorials to reflect this.

Note, for the old wildfly server the configuration of SerializationContextInitializers is not exposed, therefore it's still necessary to load instances of ProtostreamSerializationContextInitializer via the ServiceLoader in this context.