luci-app-firewall: update cbi models

 - allow multiple src/dest ips for rules (#1637)
 - restrict ICMP type list to ICMP protocol
 - add section title callbacks
 - remove size annotations
 - fix validation error with aliased zone fields (#1882)

Fixes #1637, #1882.
Signed-off-by: Jo-Philipp Wich <jo@mein.io>