feat: add Prefab provider

[liran2000]

Readme describes the provider.

solves issue 123.

* by prev. #915, as Java 11 is now supported by #1303

@jkebinger you are welcome to review

[aepfli]

Thank you. To be clear, I did not check the implementation itself. This is something that I can't challenge with too little insight. But the project setup looks great, and none of the dependencies used look suspicious to me ;). Just to be clear about what my approval means ;) and what was in my focus ;)