Add support for multiple interfaces in WAN
Related to RT #1372462
We support only one interface in WAN, we should support bridge interfaces, which can be configured in LuCI. Otherwise (re)Foris throws errors.
There is some WIP commit - https://gitlab.nic.cz/turris/foris-controller/foris-controller/-/commit/4273251814ea6398cbf88723d447bba8ecf98663/pipelines?ref=fix%2Fnetworks-pass-multiple-interfaces-on-wan