[IMP] *: replace mobile menu feature by new mobile layout

See community commit for details.

task-3060986

Part-of: odoo/design-themes#651

theme_clean/static/src/scss/primary_variables.scss

@@ -200,7 +200,6 @@ $o-website-values-palettes: (
         'buttons-font': 'Dosis',
         'header-template': 'hamburger',
         'hamburger-position': 'right',
-        'hamburger-type': 'off-canvas',
         'footer-template': 'contact',
     ),
 );