Bug 27519: Normalize Show/Don't show in system preferences

Bug 27519: Normalize Show/Don't show in system preferences

Replace Display/Don't display (and some other pairs) by Show/Don't show in system preferences.

Test plan:
1- Go to administration > system preferences
2- View any system preference with Display/Don't display pair of options
(e.g. OPACAcquisitionDetails)
3- Apply the patch
4- Refresh the page and notice it is now a Show/Don't show pair instead
5- Loop the steps with other system preferences until satisfied

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>