IPSec / routed (VTI), create virtual terminal interfaces for https://github.com/opnsense/core/issues/2332
IPSec / routed (VTI), create virtual terminal interfaces for https://github.com/opnsense/core/issues/2332

- ipsec_configure_vti() synchronizes local configuration with current ipsec% interfaces
- ipsec_interfaces() automatically adds these interfaces to the interfaces list, so the user can add a gateway and routes

opnsense/core,opnsense/core,opnsense/core,opnsense/core,opnsense/core,opnsense/core