chore(netlink): separate linux only and OS independent code

- Move `Addr` and its `String` method to `types.go`
- Move `IsWireguardSupported` to `wireguard.go` to have `family.go` OS independant
- Remove dependency on vishvananda/netlink in `ipv6.go`
- Move `Link` to `types.go`
- Move `Route` to `types.go`
- Move `Rule` and its `String` method to `types.go`

internal/netlink/address.go

@@ -1,19 +1,9 @@
 package netlink
 
 import (
-	"net/netip"
-
 	"github.com/vishvananda/netlink"
 )
 
-type Addr struct {
-	Network netip.Prefix
-}
-
-func (a Addr) String() string {
-	return a.Network.String()
-}
-
 func (n *NetLink) AddrList(link Link, family int) (
 	addresses []Addr, err error) {
 	netlinkLink := linkToNetlinkLink(&link)