Bug 19575: Rebase and fix tests

Bug 19575: Rebase and fix tests

This patch lower cases the sort by fields to normalize checking them and adjusts
some existing tests to meet the new expectations.

The regex for splitting terms has been moved into a subroutine so that adjustment was made

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit c2061adc8be1a6843c0e082c18629f4a6b8fac78)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>