Add Wireguard-based K8s pod networking

This adds a pod networking runnable based on Wireguard which watches all nodes
and adds their K8s IPAM allocations as routes into the kernel & WireGuard. It only depends
on K8s and only performs direct routing.

Test Plan: Manually tested by spinning up a two-node cluster and running two Alpine pods pinging eachother. Can be covered by E2E tests once we can do image preseeding for the test infra (T793).

Bug: T487

X-Origin-Diff: phab/D573
GitOrigin-RevId: ba3fc36f421fd75002f6cf8bea25ed6f1eb457b0
diff --git a/core/internal/common/setup.go b/core/internal/common/setup.go
index fa5cd59..6510774 100644
--- a/core/internal/common/setup.go
+++ b/core/internal/common/setup.go
@@ -34,6 +34,7 @@
 	MasterServicePort   = 7833
 	ExternalServicePort = 7836
 	DebugServicePort    = 7837
+	WireGuardPort       = 7838
 	KubernetesAPIPort   = 6443
 	DebuggerPort        = 2345
 )