Related: rhbz#1071604 don't paint anim. effect icon

... unless the slide does have custom animations. This drops dep of Draw
on libanimcore, which is in module impress, so it might not be present.
If it is not present, the Pages panel is not drawn.

Change-Id: I9d7377a4fb3289e230887752bc4a105ca1c9f812
(cherry picked from commit 90af0348216a5a3c2eecd660e012500d2917b279)
Reviewed-on: https://gerrit.libreoffice.org/9300
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>