[OB-4721] fix: Automatically hook up entity hierarchy on offline load

[MAG-ElliotMorris]

We hadn't done this. Our entity data model has a lot of duplication and only slightly different paths with super-generic naming, so it manifests bugs like this, alas. Correct by construction please.

@MAG-AdrianMeredith Thank you for providing & anonymizing the test data, that made it much simpler to get this fix up.

[github-actions]

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[MAG-SamBirley]

If the test pases with this data,. we know we've solved the problem. Thanks for jumping on this one 🙏

Agreed on the code smell but I don't know enough about the shared behaviors between online and offline to suggest a neater solve. Got ideas for the future?

[MAG-ElliotMorris]

Alas no, not in the short term.

Long term its all about the whole flattening the entity hierarchy, changing/reducing the way we load things. All the stuff we've been talking with CHS about. It's definitely accidental complexity, not essential complexity.