Add WithLoadSwIfIndex option to ipaddress chain element

[glazychev-art]

Context

networkservicemesh/cmd-nse-vl3-vpp#1

Description

We are currently using ifindex.Load(...) inside ipaddress to get the swIfIndex to set the IP-address.
For loopback interface we need to use loopback.Load instead of ifindex.Load

To make this possible, we need to add the option:

func WithLoadSwIfIndex(func(ctx context.Context, isClient bool) (value interface_types.InterfaceIndex, ok bool)) Option {...}