chore(vc): stronger p2p message abstraction

[Maddiaa0]

Overview

This PR has a lower priority, the p2p layer involves some pretty repetitive abstractions.

export class AztecTxMessageCreator {
  private readonly topic: string;
  constructor(version: SemVer) {
    this.topic = `/aztec/tx/${version.toString()}`;
  }

  createTxMessage(tx: Tx) {
    const messageData = tx.toBuffer();

    return { topic: this.topic, data: messageData };
  }

  getTopic() {
    return this.topic;
  }
}

P2P messages are created in the above way, where a tx is attached to a serialized message of the above type.

There then must exist a propogate and handle method for all differing transaction types

  public propagateTx(tx: Tx): void {
    void this.jobQueue.put(() => Promise.resolve(this.sendTxToPeers(tx)));
  }

As I understand it we will need different handle methods for each type of P2P message, however the logic to propagate a message is the same for each type of message.

As we will not have a large variety of messages, it is not a priority to rewrite the current implementation to support this, however if things expand, it will simply the code surface

[Maddiaa0]

fixed in #7733