fix: Ignore Customer Group Perm on All Products page

[marination]

Issue:

• While not logged in, if a user tries to go to the /all-products page it throws a permission error on Customer Group
• This happens precisely due to frappe.db.get_list that is used to just fetch the root customer group while getting pricing rules, nothing critical.
• It checks for permissions. Everywhere else we haven't used ORM which isn't interfering with fetching basic things
  

Fix:

• frappe.db.get_list is used due to the nature of the query (checking where parent_field is not set, more convenient with ORM)
• Let that be, ignore_permissions in it
• Product listing will be visible, while trying to add to cart user is redirected to login page