Add new channel: `SENSOR_CHAN_POS_DXYZ`, so that it is
consistent with other 3-axis channels.
Updated pytest, `sensor_shell` & `fake_sensor` accordingly.
Signed-off-by: Yong Cong Sin <ycsin@meta.com>
Update the pytest script to exercise the entire
`sensor_channel_name` table with `parse_named_int()`.
The `gauge_desired_charging_current` is selected because
it is the last one in the table before `all`, `all` is not
used because `sensor get sensor@0 all` doesn't return anything.
Signed-off-by: Yong Cong Sin <ycsin@meta.com>