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/route.go

@@ -1,22 +1,9 @@
 package netlink
 
 import (
-	"net/netip"
-
 	"github.com/vishvananda/netlink"
 )
 
-type Route struct {
-	LinkIndex int
-	Dst       netip.Prefix
-	Src       netip.Addr
-	Gw        netip.Addr
-	Priority  int
-	Family    int
-	Table     int
-	Type      int
-}
-
 func (n *NetLink) RouteList(link *Link, family int) (
 	routes []Route, err error) {
 	netlinkLink := linkToNetlinkLink(link)