feat: add UPnP NAT manager (#810)

* feat: add uPnP nat manager

Adds a really basic nat manager that attempts to use UPnP to punch
a hole through your router for any IPV4 tcp addresses you have
configured.

Adds any configured addresses to the node's observed addresses list
and adds observed addresses to `libp2p.multiaddrs` so we exchange
them with peers when performing `identify` and people can dial you.

Adds configuration options under `config.nat`

Hole punching is async to not affect start up time.

Co-authored-by: Vasco Santos <vasco.santos@moxy.studio>

test/utils/base-options.js

@@ -16,6 +16,9 @@ module.exports = {
       hop: {
         enabled: false
       }
+    },
+    nat: {
+      enabled: false
     }
   }
 }