Bug 23089: Fix sorting on sum and regular fields

Bug 23089: Fix sorting on sum and regular fields

As of bug 20589 we no longer analyze sort fields and so we no longer need to append ".phrase"
to our sort in searches.

Additionally, sort fields based on 'sum' should also use sum in building the value to sort on

To test:
0 - Be using ES
1 - Find the most circulated item in your collection
2 - Search for '*'
3 - Sort by popularity DESC
4 - Note that item is not first
5 - Try to sort by anything but relevancy, it fails
6 - Apply patch
7 - Redo searches and sorts
8 - Things should now work as expected

Signed-off-by: Ere Maijala <ere.maijala@helsinki.fi>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>