pelias pip - 'hoist' layers from pure pip results if not present in hierarchy

[missinglink]

we recently had a report that some WOF records are missing their country hierarchy entry, for example Lancing

with the 'hybrid' approach we use for the pelias PIP view, we can take values from the 'pure pip' results and use them when they are not present in the hierarchy.

See 7863cd2 for a succinct diff of the functionality change.

[missinglink]

I'm currently targeting ['country', 'dependency', 'empire', 'continent'], I wonder if adding region might be a good idea too 🤔

[orangejulius]

Yeah, this will be a huge improvement in results. I'll hold off on detailed commentary until after pelias/wof-admin-lookup#331 so we can test more fully, but I like how easy this sort of change is to make now.

I'm ok with a very limited set of hoisting for now, we could drop empire for sure, and maybe even dependency. Country is really just special because it allows adding country_codes.

[Joxit]

I think we should keep dependency, IIRC dependencies are replacing countries in some parts of the world.