WIP: add a new BETA PIP endpoint

[missinglink]

this DRAFT PR adds a new point-in-polygon endpoint which will hopefully be able to replace the existing pelias/wof-admin-lookup code.

the new endpoint returns:

• spatial matches
• hierarchies

and then for each place identified in either of the above:

• place info (source, id, class, type)
• place names (with filters for lang, tag)

initial testing shows it's slower than the /query/pip/_view/pelias/:lon/:lat endpoint but that's expected since it's doing a lot more work and returning more data.

note: the response format is subject to change