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

See community commit for details.

task-3060986

Part-of: odoo/design-themes#651

theme_artists/static/src/scss/primary_variables.scss

@@ -99,7 +99,6 @@ $o-website-values-palettes: (
         'headings-font': 'Oxygen',
         'btn-ripple': true,
         'header-template': 'hamburger',
-        'hamburger-type': 'off-canvas',
         'hamburger-position': 'left',
         'footer-template': 'centered',
         'link-underline': 'never',