[IMP] base: allow restricting / removing exports right

Add a new group allowing administrators to remove the ability for
users to bulk-export data from the database. It's pretty minor as
technically the user can still access the underlying object through
the basic methods but it's still a bit of a roadblock.

Users can export by default.

Task 2170900

closes odoo/odoo#45400

Signed-off-by: Xavier Morel (xmo) <xmo@odoo.com>