LP#1929136: delay barcode lookup on change in holdings editor

LP#1929136: delay barcode lookup on change in holdings editor

In the Holdings Editor, any change to the barcode field results in an
immediate API call.  Thus, if you type the barcode "123456789", you
would get 9 separate calls: 1, 12, 123, 1234, 12345 ...

This commit adds a 1000ms delay to avoid excessive pcrud calls when
typing a barcode.

Signed-off-by: Jeff Davis <jdavis@sitka.bclibraries.ca>
Signed-off-by: Galen Charlton <gmc@equinoxOLI.org>
Signed-off-by: Chris Sharp <csharp@georgialibraries.org>