ifconfig: l2tpv3: T1823: add missing items from config dict to options
ifconfig: l2tpv3: T1823: add missing items from config dict to options

Commit 8a4dd6c2816 ("ifconfig: T2057: add class Register") added the interface
options but not all have been migrated. The forgotten ones have been
added by this commit (session_id & peer_session_id).

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x