refactor: add core modules to libp2p (#400)

* refactor: add js-libp2p-connection-manager to repo

Co-authored-by: David Dias <daviddias.p@gmail.com>
Co-authored-by: Jacob Heun <jacobheun@gmail.com>
Co-authored-by: Pedro Teixeira <i@pgte.me>
Co-authored-by: Vasco Santos <vasco.santos@ua.pt>

* test(conn-mgr): only run in node

* refactor: add js-libp2p-identify to repo

Co-authored-by: David Dias <daviddias.p@gmail.com>
Co-authored-by: Friedel Ziegelmayer <dignifiedquire@gmail.com>
Co-authored-by: Hugo Dias <hugomrdias@gmail.com>
Co-authored-by: Jacob Heun <jacobheun@gmail.com>
Co-authored-by: Maciej Krüger <mkg20001@gmail.com>
Co-authored-by: Richard Littauer <richard.littauer@gmail.com>
Co-authored-by: Vasco Santos <vasco.santos@moxy.studio>
Co-authored-by: Yusef Napora <yusef@protocol.ai>
Co-authored-by: ᴠɪᴄᴛᴏʀ ʙᴊᴇʟᴋʜᴏʟᴍ <victorbjelkholm@gmail.com>

* refactor: add libp2p-pnet to repo

Co-authored-by: Jacob Heun <jacobheun@gmail.com>
Co-authored-by: Vasco Santos <vasco.santos@moxy.studio>

* refactor: add libp2p-ping to repo

Co-authored-by: David Dias <daviddias.p@gmail.com>
Co-authored-by: Francisco Baio Dias <xicombd@gmail.com>
Co-authored-by: Friedel Ziegelmayer <dignifiedquire@gmail.com>
Co-authored-by: Hugo Dias <mail@hugodias.me>
Co-authored-by: Jacob Heun <jacobheun@gmail.com>
Co-authored-by: João Antunes <j.goncalo.antunes@gmail.com>
Co-authored-by: Richard Littauer <richard.littauer@gmail.com>
Co-authored-by: Vasco Santos <vasco.santos@moxy.studio>
Co-authored-by: Vasco Santos <vasco.santos@ua.pt>
Co-authored-by: ᴠɪᴄᴛᴏʀ ʙᴊᴇʟᴋʜᴏʟᴍ <victorbjelkholm@gmail.com>

* refactor: add libp2p-circuit to repo

Co-authored-by: David Dias <daviddias.p@gmail.com>
Co-authored-by: Dmitriy Ryajov <dryajov@gmail.com>
Co-authored-by: Friedel Ziegelmayer <dignifiedquire@gmail.com>
Co-authored-by: Hugo Dias <mail@hugodias.me>
Co-authored-by: Jacob Heun <jacobheun@gmail.com>
Co-authored-by: Maciej Krüger <mkg20001@gmail.com>
Co-authored-by: Oli Evans <oli@tableflip.io>
Co-authored-by: Pedro Teixeira <i@pgte.me>
Co-authored-by: Vasco Santos <vasco.santos@ua.pt>
Co-authored-by: Victor Bjelkholm <victorbjelkholm@gmail.com>
Co-authored-by: Yusef Napora <yusef@napora.org>
Co-authored-by: dirkmc <dirk@mccormick.cx>

* test(switch): avoid using instanceof

* chore(switch): update bignumber dep

* refactor(circuit): clean up tests

* refactor(switch): consolidate get peer utils

* test(identify): do deep checks of addresses

* test(identify): bump timeout for identify test

* test(switch): tidy up limit dialer test

* refactor(switch): remove redundant circuit tests

* chore: add coverage script

* refactor(circuit): consolidate get peer info

* docs: reference original repositories in each sub readme

* docs: fix comment

* refactor: clean up sub package.json files and readmes

src/identify/message.js

@@ -0,0 +1,30 @@
+'use strict'
+
+const protons = require('protons')
+const schema = `
+message Identify {
+  // protocolVersion determines compatibility between peers
+  optional string protocolVersion = 5; // e.g. ipfs/1.0.0
+
+  // agentVersion is like a UserAgent string in browsers, or client version in bittorrent
+  // includes the client name and client.
+  optional string agentVersion = 6; // e.g. go-ipfs/0.1.0
+
+  // publicKey is this node's public key (which also gives its node.ID)
+  // - may not need to be sent, as secure channel implies it has been sent.
+  // - then again, if we change / disable secure channel, may still want it.
+  optional bytes publicKey = 1;
+
+  // listenAddrs are the multiaddrs the sender node listens for open connections on
+  repeated bytes listenAddrs = 2;
+
+  // oservedAddr is the multiaddr of the remote endpoint that the sender node perceives
+  // this is useful information to convey to the other side, as it helps the remote endpoint
+  // determine whether its connection to the local peer goes through NAT.
+  optional bytes observedAddr = 4;
+
+  repeated string protocols = 3;
+}
+`
+
+module.exports = protons(schema).Identify