Bug 23427: Better sorting of previous checkouts

Bug 23427: Better sorting of previous checkouts

In patron circulation or details page, previous checkouts are displayed sorted by due date.
Many checkouts may have same due date so it would be better to sort on timestamp as second sort criteria, like todays's checkouts.

Test plan :
1) Create for a patron two issues with same due date and a few seconds between them
2) Create another issue with a different due date
3) Come back a day later
4) Set preference previousIssuesDefaultSortOrder = "latest to earliest"
5) Go to patron circulation page and check sort order is OK : sorted by "Due date" then "Cheked out on"
6) Go to patron details page and check sort order is OK : sorted by "Due date" then "Cheked out on"
7) Set preference previousIssuesDefaultSortOrder = "earliest to latest"
8) Go to patron circulation page and check sort order is OK : sorted by "Due date" then "Cheked out on"
9) Go to patron details page and check sort order is OK : sorted by "Due date" then "Cheked out on"

Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>