confirmation modal for deleting an application

- adds delete-confirmation Vue component
- refactors some button styles to make them globally available

templates/fragments/admin/members_edit.html

@@ -12,7 +12,7 @@
       {% elif ppoc %}
         {% set archive_button_class = 'usa-button-disabled' %}
       {% else %}
-        {% set archive_button_class = 'usa-button-secondary' %}
+        {% set archive_button_class = 'button-danger-outline' %}
       {% endif %}
     </td>