Bug 14575: OPACURLOpenInNewWindow should apply to item-level urls too

Bug 14575: OPACURLOpenInNewWindow should apply to item-level urls too

This patch applies the OPACURLOpenInNewWindow system preference
to item-level urls (in addition to the pre-existing bib-level url
handling).

_TEST PLAN_

Before applying:

1) Set OPACURLOpenInNewWindow to "don't" and click on an item-level url
2) Note that the current tab changes to that url
3) Set OPACURLOpenInNewWindow to "do" and click on an item-level url
4) Note that the current tab changes to that url

Apply the patch.

After applying:

5) Click on an item-level url
6) Note that the url opens in a new tab (as OPACURLOpenInNewWindow
should be set to "do")
7) Set OPACURLOpenInNewWindow to "don't" and click on an item-level
url
8) Note that the url opens in the current tab

9) Repeat the above steps 5-8 alternating
"TrackClicks" between "Don't track" and either "Track" or
"Track anonymously".

Followed test plan. Works as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>