chore: make `waitForRemotePeer` part of the `waku` interface

[danisharora099]

This is a change request

Problem

The current waitForRemotePeer utility takes in waku as the first argument. This function needs to be imported separately and then the node is passed to this function.

Proposed Solutions

It is much easier to just make waitForRemotePeer part of the waku class, and directly callable like node.waitForRemotePeer() thus also reducing one argument passed to the function.

[chair28980]

Note from js-waku pm 2023-12-20:

Might be a good idea to use this function within the node.start function.