feat: Maintain non full-mesh peerings for each topic/shard

[chaitanyaprem]

Problem

With #727 , peer-manager ensure min of D peers are maintained.
But, in order for gossipSub to be efficient, metadata only peers are also to be maintained.
This doesn't impact any performance with current approach but in long run may have an impact on serviceNode and relay nodes.

But, this information of whether a peer is fullMesh or metadata only is not available at Waku-layer and hence would require changes to go-libp2p-pubsub to expose this info so that peerManager can take decisions accordingly.

Suggested solution

To be analyzed if there are any alternatives.

Acceptance criteria

Verify that both fullMesh and metadata only peer connections are maintained for all subscribed shards or pubSubTopics.

[chaitanyaprem]

Closing the issue as it is descoped for go-waku.