daemon: Allow to specify dev to inherit IP addr for LB devs

[brb]

This commit introduces a new daemon flag --bpf-lb-dev-ip-addr-inherit
which allows to specify a device name which IP addr is used for
--devices in bpf_host.c (IP{4,6}_NODEPORT).

This is useful for cases in which NIC ifaces w/o IP addrs are connected
to a bridge which has an IP addr set, and IP{4,6}_NODEPORT addr should
be of the bridge.

Fix #14226

[brb]

retest-net-next

[borkmann]

I think commit description should say IPV4_DIRECT_ROUTING and/or IPV6_DIRECT_ROUTING, no? Given we use these in particular for SNAT.

At least we pick them here based on nodePortIPv4Addrs():

                if option.Config.EnableIPv4 {
                        nodePortIPv4Addrs := node.GetNodePortIPv4AddrsWithDevices()
                        ipv4 := byteorder.HostSliceToNetwork(nodePortIPv4Addrs[directRoutingIface], reflect.Uint32).(uint32)
                        cDefinesMap["IPV4_DIRECT_ROUTING"] = fmt.Sprintf("%d", ipv4)
                }

[brb]

I think commit description should say IPV4_DIRECT_ROUTING and/or IPV6_DIRECT_ROUTING, no? Given we use these in particular for SNAT.

Created an issue to remove IPV{4,6}_NODE_PORT: #14273.

[brb]

test-me-please

[brb]

retest-net-next