add Previous link to Project > Stacks table

Stack list API supports a sort direction and sort key which we can
use to paginate back

Following same convention as merged patch:
https://review.openstack.org/#/c/91111/

Change-Id: I511d7d27a6234e1510c7fa3c7f84c007599f3721
Partially-implements: blueprint pagination-add-prev-link
Merge "add Previous link to Project > Stacks table"