Implement user search widget with HTMX for dynamic user selection

generic/templates/generic/partials/user_search_widget_results.html

@@ -0,0 +1,14 @@
+{% if results %}
+  <ul class="list-unstyled mb-0">
+    {% for item in results %}
+      <li class="py-1 d-flex justify-content-between align-items-center">
+        <div class="flex-grow-1">{{ item.text|escape }}</div>
+        <div>
+          <button type="button" class="btn btn-sm btn-primary" onclick="addUserToField('{{ field }}', {{ item.id }}, '{{ item.text|escapejs }}')">Add</button>
+        </div>
+      </li>
+    {% endfor %}
+  </ul>
+{% else %}
+  <div><em>No users found</em></div>
+{% endif %}