Commit 55a48e3 added support for computing car count and car reports
for employees without a linked user..
It is computed by accessing the field `address_home_id` (res.partner) to find the driver.
However, this field is private.
Therefore a user in `fleet_group_manager` has an ACL error when accessing
an employee form view which contains a stat button with the car count.
This commit compute the car count and the car report
with `address_home_id` as sudo to fix the issue.
Also fix a typo in attribute `groups` instead of `group` and fix its
value from `fleet_manager` to `fleet.fleet_group_manager`.
Lucas Lefèvre
607fd63545