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/core/consume-peer-record.spec.js

@@ -0,0 +1,46 @@
+'use strict'
+/* eslint-env mocha */
+
+const Transport = require('libp2p-websockets')
+const { NOISE: Crypto } = require('libp2p-noise')
+
+const Libp2p = require('../../src')
+const { createPeerId } = require('../utils/creators/peer')
+
+describe('Consume peer record', () => {
+  let libp2p
+
+  beforeEach(async () => {
+    const [peerId] = await createPeerId()
+    const config = {
+      peerId,
+      modules: {
+        transport: [Transport],
+        connEncryption: [Crypto]
+      }
+    }
+    libp2p = await Libp2p.create(config)
+  })
+
+  afterEach(async () => {
+    await libp2p.stop()
+  })
+
+  it('should consume peer record when observed addrs are added', async () => {
+    let done
+
+    libp2p.peerStore.addressBook.consumePeerRecord = () => {
+      done()
+    }
+
+    const p = new Promise(resolve => {
+      done = resolve
+    })
+
+    libp2p.addressManager.addObservedAddr('/ip4/123.123.123.123/tcp/3983')
+
+    await p
+
+    libp2p.stop()
+  })
+})