this change means simple sort requirements no longer require
importing the search package (high-level API goal)
also the sort test at the top-level was changed to use this form
previously from JSON we would just deserialize strings like
"-abv" or "city" or "_id" or "_score" as simple sorts
on fields, ids or scores respectively
while this is simple and compact, it can be ambiguous (for
example if you have a field starting with - or if you have a field
named "_id" already. also, this simple syntax doesnt allow us
to specify more cmoplex options to deal with type/mode/missing
we keep support for the simple string syntax, but now also
recognize a more expressive syntax like:
{
"by": "field",
"field": "abv",
"desc": true,
"type": "string",
"mode": "min",
"missing": "first"
}
type, mode and missing are optional and default to
"auto", "default", and "last" respectively
The syntax used is an array of strings. The strings "_id" and
"_score" are special and reserved to mean sorting on the document
id and score repsectively. All other strings refer to the literal
field name with that value. If the string is prefixed with "-"
the order of that sort is descending, without it, it defaults to
ascending.
Examples:
"sort":["-abv","-_score"]
This will sort results in decreasing order of the "abv" field.
Results which have the same value of the "abv" field will then
be sorted by their score, also decreasing.
If no value for "sort" is provided in the search request the
default soring is the same as before, which is decreasing score.
