feat(node): [NET-1381] Add version to operator heartbeats

[teogeb]

Add applicationVersion field to the heartbeat message (published by announceNodeToStream).

Testing

Manually tested that the schema validation in v101 accepts the message which has the additional version field. This test snippet passes in a temp branch which was checked out from the v101.1.2 tag:

it('v102 messages passes validation in v101 schema', () => {
    const msg = {
        "msgType": "heartbeat",
        "peerDescriptor": {
            "nodeId": "nodeId",
            "websocket": {
                "port": 31313,
                "host": "127.0.0.1",
                "tls": false
            }
        },
        "applicationVersion": "102.0.0-beta.1"
    }
    expect(() => HeartbeatMessageSchema.parse(msg)).not.toThrow()
})

[linear]

NET-1381 Add version to operator heartbeats

[mondoreale]

Looks good. See comments.