[IMP] test_themes, theme_* : Adapts tours for new dragNDrop system

Following the change in the way of dragging and dropping a snippet onto
the page (by selecting it from a dialog displaying the actual previews
of snippets). The themes tours have been adapted to this change in this
commit.

task-3919405

closes odoo/design-themes#817

Related: odoo/odoo#166967
Related: odoo/enterprise#66150
Signed-off-by: Robin Lejeune (role) <role@odoo.com>

theme_nano/static/src/js/tour.js

@@ -6,26 +6,32 @@ const snippets = [
     {
         id: 's_cover',
         name: 'Cover',
+        groupName: "Intro",
     },
     {
         id: 's_features',
         name: 'Features',
+        groupName: "Content",
     },
     {
         id: 's_text_block',
         name: 'Text',
+        groupName: "Text",
     },
     {
         id: 's_images_wall',
         name: 'Images Wall',
+        groupName: "Images",
     },
     {
         id: 's_parallax',
         name: 'Parallax',
+        groupName: "Images",
     },
     {
         id: 's_references',
         name: 'References',
+        groupName: "People",
     },
 ];