Disconnect old peers, cleanup node and improve timeouts - Closes #1086

[jondubois]

What was the problem?

• There was no mechanism to fully disconnect from peers which could not be reached.
• There was an issue in the integration tests which meant that P2P node would not aways stop correctly.
• There was no mechanism for configuring timeout values on the P2P node.

How did I fix it?

• If a peer cannot be reached from our outbound connection, we remove them from our PeerPool. It's possible that the node may try again at a later time when the next round of discovery will run; this is configurable by the user.
• Fixed a bug related to a missing option passed to the client socket which means that sockets were being reused and event handlers were accumulating on them.
• Added an new ackTimeout to allow the user to specify an upper bound on how long it should take to perform requests (including discovery).
• Cleanup issue related to the P2P stop() method not resolving in some scenarios.
• Added an integration test case to verify that stopping one of the P2P nodes in the network causes other peers to remove that node from their PeerPool.

EDIT (after PR feedback)

• The isDiscoveredPeer property is now compulsory on the P2PDiscoveredPeerInfo interface because we need to always differentiate between these two objects internally.
• The P2P node now makes a peer.fetchStatus() 'status' call after connecting on the outbound connection; we need to make this call in order to get the full P2PDiscoveredPeerInfo from the outbound connection.
• Changed _triedPeers to be of type Map<string, P2PDiscoveredPeerInfo> (only the full discovered peers info is allowed); we should not have undiscovered peers in there as it will cause issues in other parts of the logic.
• _triedPeers is now populated using a new event on the PeerPool called EVENT_DISCOVERED_PEER; this event carries the full P2PDiscoveredPeerInfo
• Improved the solution for the P2P stop() method not resolving.

How to test it?

npm run test:integration

Review checklist

• The PR resolves #1086
• All new code is covered with unit tests
• All new code was formatted with Prettier
• Linting passes
• Tests pass
• Commit messages follow the commit guidelines
• Documentation has been added/updated

[shuse2]

@jondubois Also, it's failing on Jenkins with

@liskhq/lisk-p2p: test/unit/peer_discovery.ts(54,52): error TS2345: Argument of type 'P2PPeerInfo[]' is not assignable to parameter of type 'ReadonlyArray<P2PDiscoveredPeerInfo>'.

@liskhq/lisk-p2p:   Property 'version' is missing in type 'P2PPeerInfo' but required in type 'P2PDiscoveredPeerInfo'.