Bug 27680: Add support for sorting fields with multiple data points
This patch adds proper handling for sorting a single column that is
constructed of multiple data entities.. i.e `"data": "string1:string2"`
It does NOT add support for filtering on multiple columns yet.
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io> Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org> Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>