Move gossip validation logs to debug

[dapplion]

Running a beacon node with general verbose log level gets destroyed by gossip validation logs, you can't see anything else. This PR:

• Removes the "starting validation" log
• Moves all logs to debug level

In addition we should review:

• is it necessary to log the full error stack trace when an attestation is already known?

2021-03-18 14:00:58 [NETWORK]          warn: Ignoring gossip aggregate and proof attestationSlot=770970, aggregatorIndex=5536, aggregateRoot=0xe2095a279e80ba484e2052014f43787b86a1aac589d1f1e22fd152a24a350c11, attestationRoot=0x41eb5ecb3bd537b18d28820eb3e5dcef92aa889d5cb39d9234d5accfb95a24cc, targetEpoch=24092 code=ATTESTATION_ERROR_PAST_SLOT, earliestPermissibleSlot=770979, attestationSlot=770970
Error: ATTESTATION_ERROR_PAST_SLOT
    at validateGossipAggregateAndProof (/usr/app/packages/lodestar/src/chain/validation/aggregateAndProof.ts:27:11)
    at validatorFn (/usr/app/packages/lodestar/src/network/gossip/validator.ts:173:13)
    at /usr/app/packages/lodestar/src/network/gossip/gossipsub.ts:113:38
    at LodestarGossipsub.validate (/usr/app/node_modules/libp2p-gossipsub/node_modules/libp2p-interfaces/src/pubsub/index.js:559:13)
    at LodestarGossipsub.<anonymous> (/usr/app/node_modules/libp2p-gossipsub/src/index.js:327:39)
    at Generator.next (<anonymous>)
    at /usr/app/node_modules/libp2p-gossipsub/src/index.js:27:71
    at new Promise (<anonymous>)
    at __awaiter (/usr/app/node_modules/libp2p-gossipsub/src/index.js:23:12)
    at LodestarGossipsub.validate (/usr/app/node_modules/libp2p-gossipsub/src/index.js:325:16)

• is it necessary to log so much about the attestation in the logs? What the minimum info necessary to know about the attestation at this level?

[codeclimate]

Code Climate has analyzed commit 1822944 and detected 2 issues on this pull request.

Here's the issue category breakdown:

Category	Count
Duplication	2

View more on Code Climate.