Bug 42014: Show empty state message on patron lists tab

- When no patron lists exist in the system, the patron lists
  tab on the patron detail page renders completely blank
- Other tabs follow the convention of showing a message in
  the empty state (e.g. "Patron has nothing on hold.")
- Add an empty state message with a link to create a new
  patron list, matching the established pattern

To test:
- Go to a patron detail page and click the "Patron lists" tab
- If no patron lists exist, observe the tab is blank
- Apply patch
- Repeat the above steps
- Verify the tab now shows "Patron is not on any list." with
  a link to create a new patron list
- Click the link and create a patron list
- Return to the patron detail page and verify the "Add patron
  to list" dropdown now appears instead

Signed-off-by: Owen Leonard <oleonard@myacpl.org>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Laura Escamilla <laura.escamilla@bywatersolutions.com>

koha-tmpl/intranet-tmpl/prog/en/modules/patron_lists/patron-lists-tab.tt

@@ -119,6 +119,8 @@
         </select>
         <a onclick="addToList()"><i class="fa fa-plus"></i></a>
     </div>
+[% ELSIF CAN_user_tools_manage_patron_lists %]
+    <p>Patron is not on any list. <a href="/cgi-bin/koha/patron_lists/add-modify.pl">Create a new patron list</a>.</p>
 [% END %]
 <script>
     var patron_lists_dt_params = {