Replicate multiple feeds on a single colmeiad instance

[bltavares]

The colmeia-hyperdrive crate is conflating the storage, peering, hyperdrive and hypercore code.

With @Frando's upcoming hypercore-replicator, we should be able to handle multiple replicated feeds, and we can focus on writing only the hyperdrive code, without conflating that much.

TODO Next livestream:

• Split colmeia-hypercore into colmeia-hyperdrive, and only use hyperdrive code.
• Adopt hypercore-replicator from @Frando on hyperstack
• Adopt updated hyperstack on colmeiad
• Bonus: Change protobuf crate to use the same as hypercore protocol (reduce dependencies) PROST depends on protoc