Support ID-INT in SEED

Add support for ID-INT https://github.com/netsys-lab/scionproto-scion/tree/idint

Depends on https://github.com/netsys-lab/seed-emulator/pull/3
ID-INT adds new BR configuration options that need to be supported by https://github.com/netsys-lab/seed-emulator/issues/5

ID-INT PR (WIP) in our SCION fork: https://github.com/netsys-lab/scionproto-scion/pull/1