Retrieve study and retrieve series are not retrieving correct list of instances

[dannyrb]

See: OHIF/Viewers#736

[hackermd]

@MathisGuilhin reported:

When I use retrieveSeries or retrieveStudy, only the first instance of DICOM is readable.
It actually gives back a list of instances as arraybuffers, but only the first one is readable (or maybe im not doing it right).

[hackermd]

@swederik could this be the problem?

dicomweb-client/src/message.js

Line 192 in f0b3086

const maxSearchLength = 1000;