Bug 31806: Add page-section to holds tables

Bug 31806: Add page-section to holds tables

This patch adds the page-section class to each holds view on
reserve/request.pl

Test plan
1) Find an biblio to test on and add holds items of different types and
   homebranches.
2) Work through each setting of the HoldsSplitQueue preference and
   confirm the page-sections appear as expected

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>