Add more integration tests for P2P library

[jondubois]

Expected behavior

We need integration tests to cover the following features:

Peer discovery

• When the network starts all at once and disconnected without any seed nodes.
• When the network starts all at once and each node uses its next neighbour as a seed node.
• When network starts disconnected and where nodes are added one at a time; each node uses its previous neighbour as a seed node.
• When the network starts all at once; each node shares the same seed node.
• When the network starts disconnected and nodes are added one at a time; each node shares the same seed node.

P2P.request

• Should make request to the network; it should reach a single peer.
• Should be able to receive a response from the network; from a single peer.

P2P.send

• Should send a message to a subset of peers within the network; should reach multiple peers.

P2P.applyNodeStatus

• Should send our node status to a subset of peers within the network.

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To make it easier to set up the tests (I.e. beforeEach and afterEach block), they should be divided based on network topology:

• Disconnected network
• Partially connected network
• Fully connected network

Actual behavior

Missing integration tests.