QIDO-RS does not respect limit and offset parameters

[swederik]

From @pieper, it looks like the limit and offset parameters are not being applied.

[lassoan]

This causing an issue at various places:

• Slicer's DICOMwebBrowser queries list of studies in batches, increasing the offset by the number of studies received, until no new studies are received. This loop runs infinitely, as the offset parameter is ignored.
• OHIF viewer can only shows the first 25 studies (max 100, if you set rows per page to 100), clicking "Next" has no effect at all

This essentially renders the OHIF viewer unusable for any data collection that contain more than 100 studies.

[swederik]

Looks like we just need to fix the slice call here: https://github.com/dcmjs-org/dicomweb-server/blob/6bfcb26dabf2b7c4f114b627a87eb4915b18f7cc/plugins/CouchDB.js#L270