Support arrays for item filters

[rockliffelewis]

As of 3.1.0-rc1 the supported data types for item filters are numerics, text, and booleans, which is applicable for the majority of cases, however one of the core fields of instrument is an array of strings (spec here)

It would be great to add support for this so that people can filter based on instrument types

[m-mohr]

It might be that some implementations allow equal comparison for arrays, but "IN" would be better, indeed.
There's a draft PR for it, see #339. It's not ready to be merged and I'm lacking funding to further work on it, unfortunately.