Shallow multi edge

[FmeuMan]

Should do the work for #528.
Dont know if is it worth it to handle collections with both entities and shallow entities. This doesn't work for now.

[bartoszwalacik]

Hi @FmeuMan, nice PR but needs some work.
I have committed a failing test here #805

looks like we need to add support for class-level @ShallowReferecne:

The case:

class SnapshotEntity {
    Set<ShallowPhone> shallowPhones
}

@ShallowReference
public class ShallowPhone {
}

[FmeuMan]

Nice one! I'll take a look.
And thanks for the reformating :)

[FmeuMan]

Ok! Thoses additions seems a bit intrusive to me. But I don't think i can do better for now

[bartoszwalacik]

@FmeuMan I have added more test on my branch, also I did some refactoring to make this new feature more aligned with javers-core. My branch is merged and I will release it tomorrow.
So I'm closing this branch, and finally, your last commit won't be merged.

Thanks for your contribution, you have great understanding of Javers code base and tests. Your PRs are welcome.