LPS-48733 Adding registry for xstream aliases

Hey Miguel,

You have removed the aliases from the export/import a while ago, due to modularity concerns. I wanted to add those back with a proper solution for a modular approach.

I've coded a registry based on the other registries as well because they have been completely changed lately. It's pretty much straightforward, except one thing, I've added a private class to the registry as a helper - the XStreamAlias. I didn't want to expose this as an API, it's just a helper stuff, nothing the consumer of this class should worry about.

I've added an example usage as well, the rest of the changes are very basic.

Can you please review the registry class primarily? Let me know if you have any questions.

Thanks,

Máté