added tests, preparing submission confirmation

src/main/java/de/srsoftware/widerhall/web/Rest.java

@@ -53,7 +53,12 @@ public class Rest extends HttpServlet {
             json.put(USER,user.safeMap());
             switch (path) {
                 case USER_LIST:
-                    json.put("users", (user.is(ADMIN) ? User.list() : List.of(user)).stream().map(User::safeMap).toList());
+                    try {
+                        json.put("users", (user.is(ADMIN) ? User.loadAll() : List.of(user)).stream().map(User::safeMap).toList());
+                    } catch (SQLException e) {
+                        LOG.debug("Failed to load user list:",e);
+                        json.put(ERROR,"failed to load user list");
+                    }
                     break;
                 case LIST_LIST:
                     json.put("lists", MailingList.listsOf(user).stream().map(MailingList::safeMap).toList());