default protocol from filter to relay, additional content topic filter

[hopeyen]

Description

• Changed default behavior of protocol participation - now radio nodes will automatically participate in relay protocol and directly subscribe and publish to relay network
• Updated network_check to connect to peers on the relay network and disregard connecting with lightpush and filter peers
• Added an additional check to only handle messages of relevant content topics
• Changed content topics to be in a std mutex instead of tokio mutex in order to use content topics upon signal handling in the waku event callback
• Updated and tested with ping-pong example

Issue link (if applicable)

Resolves #295

No significant updates should be needed for dependent radios

Checklist

• Are tests up-to-date with the new changes?
• Are docs up-to-date with the new changes? (Open PR on docs repo if necessary)

[chriswessels]

This was quick. Great work. Do we need to notify the infra team of any bootnode config changes?

[hopeyen]

This was quick. Great work. Do we need to notify the infra team of any bootnode config changes?

Thanks! No need to notify, the bootnodes are already on relay. We could turn off filter on bootnodes but that's not necessary, we will have to notify pubsub topic config changes if we do sharding later.