Extend the keyword index. Add barcode to Keyword search in Inventory. Display holdings and item record directly with exact match - Phase 1

Overview: Request from Chalmers:
When searching in Inventory I want to have the most common ways to search in the Keyword search. To find the item record for a specific copy (a common task in the circulation desk) the easiest way is to search using the barcode. After the Q4 release that requires more clicks than before and the staff has begun to complain.

Developer comments by jakub:
Extend the keyword index
This is a backend solution that would extend "keyword" index definition to also include "barcode". In this case the query remains keyword all "xxx" and it's possible to combine barcode searches with other searches e.g Harry Potter 1234. The drawback is that "barcode" would be matches according to the full-text rules, so if there are any spaces or special characters in the barcode (I don't think there are?) it might behave weird.

Instance segment:

Holdings segment:

Item segment:

Search on item barcode result in one item barcode. There is a user requirement to have the item record displayed directly, and users want to skip the display of the 2nd pane, and the instance with item detailed list in the top.
This is a breaking change to the general UX consistency, but similar display might be introduced in other apps; e.g. MARC authorities.

Tweak of current display:

Display when we have implemented the hierarchical display of the result list: