settings: zms: fix some bugs related to the name's ID

To avoid collisions between IDs used by settings and IDs used directly
by subsystems using ZMS API, the MSB is always set to 1 for Setting's
name ID written to ZMS backend

Add as well a recovery path if the hash linked list is broken.

Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>