use libpostal parses for venue queries where available

[missinglink]

We're currently not using libpostal parses for venues, if we see a venue parse we're falling back to the native parser.
I don't remember the history of this but it seems wrong to me 🤷‍♂

I noticed this when looking into some bug reports, one example being "Café Pelias".
There are two things currently going wrong with this query:

• libpostal parses it correctly but the query fails with the message No query to call ES with. Skipping
• upon falling back to the native parser it parses it incorrectly (I'll open a separate issue for this on that repo)

So regarding the first point, I don't see why we would throw away the venue parse here from libpostal:

"parsed_text": {
  "query": "Café Pelias"
}

The query label has actually been mapped from the libpostal house field in controller/libpostal, but this field indicates a venue name.

As you can see from the PR edits, we don't currently consider these venue parses for query generation and I'm not sure why, I believe that libpostal is still superior to the native parser when it comes to venue queries and has always been better than addressit was?

Thoughts?

[missinglink]

The only reason I can think of for the existing behaviour is if libpostal erroneously identifies things as house and we were trying to guard against that?

[missinglink]

I rebased this and put it up on dev today, it fixes the "vanity addresses" issue we've been discussing:

cc/ @blackmad

[missinglink]

linked pelias/acceptance-tests#533

[missinglink]

I ran the full acceptance test suite on this today and there were actually quite a few improvements, but at the same time it highlighted some issues.

diff of changes vs. production: https://www.diffchecker.com/5Faotyih (ignore any errors related to /v1/reverse)

screenshots of some issues inherited from libpostal:

[orangejulius]

Yeah, I suspect there are two reasons why this was never implemented in the past:

• a lot of our early libpostal work was done with little concern for venues, we were really thinking mostly about addresses
• There are surely many cases where libpostal doesn't do a great job accurately detecting venues. Either false positives or false negatives would impact results in ways that are difficult to fix.

The first reason is obviously not a good one, but I imagine the hard part of actually merging this will be ensuring there aren't too many cases where, for example, something that is very much not a venue query, like one for an admin area or address, will be made worse.

[missinglink]

Right, so the question is "which parser does a better job of venues?" and the answer is "no" 😆