This is the first PR in support of
https://github.com/ledgerwatch/erigon/issues/5824.
The phase 0 sepc
https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#global-topics
specifies 6 global pubsub topics that CL nodes need to handle.
This PR implements the `beacob_aggregate_and_proof` topic:
https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#beacon_aggregate_and_proof.
The `AggregateAndProof` and `SignedAggregateAndProof` types are defined
here:
https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/validator.md#aggregateandproof.
I followed the implementation of `SignedBeaconBlockBellatrix`, which has
the following references:
1. cmd/lightclient/cltypes/types.go: defines the struct with relevant
SSZ annotations on the fields.
2. cmd/lightclient/cltypes/clone.go: this just returns a reference to an
empty object, so not super clear to me if it is necessary:
3. cmd/lightclient/rpc/common.go: this decodes gossip data, switching on
the type of gossip message that is received.
4. cmd/lightclient/sentinel/service/service.go: this listens on the
pubsub channel and notifies when a packet of the relevant type comes in.
5. cmd/lightclient/sentinel/pubsub.go: this defines the gossip topic
struct.
6. cmd/lightclient/lightclient/subscriber.go: this is the lightclient
interface for the incoming messages that come from the sentinel.
Now we are sending correct metadata responses
We disconnect from peer no matter if we fail to respond to them once we
receive a goodbye message
We close all writers once we are done writing to signal our peer
