[IMP] website: add helper next to visibility field when set to group

Commit [1] introduced a way to "hide" an ir.ui.view through a new
visibility field.
That field has multiple possible values to restrict the access. One of
those is "Restricted Groups", but when selected it's really hard to
figure what to do next because nothing happens on screen: there is no
"groups" field where to add the groups.

Those groups should actually be added a bit below, in the groups_id
field which is "hidden" inside the "Access Rights" second tab.
This is because the groups_id field already existed (in base module)
before introducing the website visibility feature which just relied on
that field when set to "Restricted Groups".

Note that another possible value for visibility is "Password", and in
this case a password field appear below the visibility field as one
would expect.

[1]: https://github.com/odoo/odoo/commit/e239934abe456257c9dc285d1ad9829c0353900c

closes odoo/odoo#151602

Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/website/i18n/website.pot

@@ -1662,6 +1662,11 @@ msgstr ""
 msgid "Add a new field at the end"
 msgstr ""
 
+#. module: website
+#: model_terms:ir.ui.view,arch_db:website.view_view_form_extend
+msgid "Add groups in the \"Access Rights\" tab below."
+msgstr ""
+
 #. module: website
 #. odoo-python
 #: code:addons/website/models/res_lang.py:0

addons/website/views/website_pages_views.xml

@@ -191,6 +191,10 @@
             <field name="page_ids" invisible="1" />
             <field name="first_page_id" invisible="not page_ids" />
             <field name="visibility" invisible="type != 'qweb'" />
+            <span class="o_wrap_label" invisible="visibility != 'restricted_group'"/>
+            <div class="oe_edit_only alert alert-info" role="alert" invisible="visibility != 'restricted_group'">
+                Add groups in the "Access Rights" tab below.
+            </div>
             <field name="visibility_password_display" invisible="visibility != 'password'" password="True" string="Visibility Password" />
         </field>
         <sheet position="before">