* feat: update lightpush API to make pubSubTopic optional as per autosharding
* Extract contentFilter and subscriptions out of filter to reuse in relay (#779)
* chore: extract contentFilter outside filter package
* chore: move subscription outside of filter so that it can be modified and reused for relay
* Feat: filter select peer for sharding (#783)
* update selectPeer to support pubsubTopic based selection
* chore: add shard choice simulation test
* feat: add new flags for pubsub and contentTopics and deprecate topic flag
* chore: remove store-resume-peer config and comment out functionality until redesign of store is done
* chore: fix code to use contentTopics value
* fix: use default waku topic only if no other topics are provided in the config
- Shards in same cluster are advertised on ENR
- Store().Resume() was moved to app layer
- NoDefaultWakuTopic() was removed since it's the app that must determine whether it subscribes to the default waku topic
- Removed `Publish` from WakuNode (not really used and easy to implement in app layer if needed)