Timeout errors come back from the Elasticsearch module as Error objects,
so instead of pushing the entire object onto the errors array, we should
just push the message.
I'm not sure if there are other cases where errors are just strings,
errors that aren't objects with a message property are handled as
before.
It turns out the _type parameter to the Elasticsearch
[multiget](https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-multi-get.html)
API does not allow an array of possible values. We were depending on its
ability to search multiple types to allow searching for OSM nodes and
ways.
But, since this doesn't work we essentially have to do it ourselves.
There is also the problem that OSM nodes and ways share an ID space. So
a gid such as `osm:venue:5` could in theory correspond to 2 records.
It seems like the only nice thing to do in that case is return both
results.
This PR "unrolls" such queries. For example, in the case of
`osm:venue:5`, the sanitisers will return the following array of objects
to be turned into multiget queries:
```
[{
id: 5,
types: ["osmway", "osmnode"]
}]
```
Before, this would turn into a multiget query with only one entry, like
this:
```
{
"docs": [
{
"_index": "pelias",
"_type": [
" osmnode",
"osmway"
],
"_id": 5
}
]
}
```
now it would look like this:
{
"docs": [
{
"_index": "pelias",
"_type": "osmnode",
"_id": 5
},
{
"_index": "pelias",
"_type": "osmnode",
"_id": 5
}
]
}
TLDR you might get back more records from /place than the number of ids
you specified, but at least you will definitely get back what you are
looking for.
This middleware looks at the list of types that will be sent to
Elasticsearch, if it's an empty array, it sends an error response before
Elasticsearch is even quieried, because Elasticsearch interprets an
empty type array as "search anything" rather than the intended "don't
search anything".