Bug 34373: Improve layout of curbside pickups items ready list

Bug 34373: Improve layout of curbside pickups items ready list

This patch adds fieldset + list markup around the list of titles ready
for pickup on the staff interface curbside pickup page.

- Properly testing requires testing data. You can run this command to
  REPLACE your curbside pickup data with sample data:

  bash <(curl -s https://gitlab.com/-/snippets/2572579/raw/main/test_curbside_pickups.sh)
- Apply the patch and restart services.
- Place multiple holds for a single patron and check them in to mark
  them waiting.
- Under Circulation -> Curbside pickups, click the "Schedule pickup"
  tab.
  - Search for the patron you placed the holds for.
  - When the patron information comes up, the list of items ready for
    pickup should be well-formatted.

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>