[FIX] web: add Shortcut CTRL+K in user menu

Purpose:
Make the command palette easier to discover - indeed, unless you
know about CTRL+K, it's difficult to know you can use that elsewhere
than the home screen.

Solution:
Add CTRL+K next to the Shortcut menu in the user menu.

closes odoo/odoo#106594

Tackid: 3074492
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>