feat: Service peer selection on specific shards

[chair28980]

Currently a service peer (e.g. a store node) is either provided by the application or it expects the peer manager to suggest a suitable service peer (selectPeer()). This task focuses on the latter: peer manager should provide ability to find service peers for a specific shard, based on the content topic that the application is interested in (e.g. an API call to selectPeer(Protocol, ContentTopic)), or kick off an ad-hoc discovery process until a suitable service peer is found. Client APIs (for filter, lightpush, peer-exchange) should automatically make use of this mechanism if the application does not explicitly set the desired service peer.

Priority: critical for launch

Tasks

• Feat: filter select peer for sharding #783
• Update peer selection options for light protocols #787
• feat: On Demand Peer Discovery based on shard and service #834

[chaitanyaprem]

Weekly Update

• achieved: Peer selection updated to be based on pubsubTopic or contentTopic
• next: Update lightClient API to consider new peerSelection options

[chaitanyaprem]

Weekly Update

• achieved: refactor and migrate peer selection to peer manager and update lightclient API to use new options
• next: on-demand discovery if peers are not available for the shard

[chaitanyaprem]

Weekly update

• achieved: draft PR feat: On Demand Peer Discovery based on shard and service #834 opened for on-demand peer discovery
• next: use on-demand peer discovery for service and relay peer selection

[chaitanyaprem]

Weekly update

• achieved: on-demand peer discovery for service peer selection and new relay shard subscriptions