Bug 26484: Add serials-related reports to serials sidebar menu

Bug 26484: Add serials-related reports to serials sidebar menu

This patch adds a section to the serials sidebar menu for showing
serials reports.

To test, apply the patch and go to Serials.

- If you are logged in as a user with permission to access reports you
  should see a new "Reports" heading in the sidebar menu and a link to
  the serials statistics wizard.
- Confirm that the link works correctly.
- Log in as a user without reports permission and confirm that the
  section doesn't appear.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>