settings_core_load() function

For Provisioner, the load operation needs the following actions: role_set: Need, restore the device role net_set: Not needed iv_set: Need, restore the last IV Index status seq_set: Need, restore the previous sequence number rpl_set: Need, restore the previous Replay Protection List net_key_set: Not needed app_key_set: Not needed hb_pub_set: Not needed currently cfg_set: Not needed currently sig_mod_set: Need, restore SIG models related info (app, sub, pub) vnd_mod_set: Need, restore vendor models related info (app, sub, pub) va_set: Not needed currently