Waku Peer Exchange Overhaul

[kaiserd]

Background

This milestone issue tracks various issues and tasks updating the Waku peer exchange protocol.

The goals are

• several minor improvements and adjustments (see task list below),
• simplifying the protocol moving to a resq/resp protocol, and
• transitioning 34/WAKU2-PEER-EXCHANGE to draft state.

The current design was chosen to allow PX service nodes to retrieve peers on demand,
and sending peer information to requesters once obtained.

The new design requires peers to manage a px peer cache, and retrieve peers asynchronously.
This was the default, with the current design, too.
So, the new design only removes the on-demand option, while simplifying the protocol design.
The simpler design is especially desired by restricted devices (e.g. Browser), for which the peer exchange protocol was designed in the first place.

Issues and Tasks

• chore(networking): decouple discovery, add peers and connect to them waku-org/nwaku#1463
• Peer Exchange protobuf improvements waku-org/waku-proto#14
• update 34/WAKU2-PEER-EXCHANGE to req/resp
• nwaku implementation
• js-waku implementation
• interop test
• promote 34/WAKU2-PEER-EXCHANGE to draft

Notes and Prior Discussion

• chore(peer-exchange): connection establishment waku-org/nwaku#1301
• peer-exchange: js-waku <> nwaku interop waku-org/nwaku#1408

[kaiserd]

Ownership of most parts of this issue has been moved to Waku: waku-org/pm#101