Implement consensus reward statistics collector subsystem

[EclesioMeloJunior]

Issue summary

In an epoch $e$, each validator $u$ counts of the number $\alpha_{u,v}$ of votes they used from each validator $v$, including themselves. Any time a validator marks a candidate approved, they increment these counts appropriately.

We should create a subsystem capable of collect useful approvals usage and availability distribution downloads and uploads

DoD

• Create the subsystem collection
• Collect useful approvals
• Collect downloaded chunks
• Collect uploaded chunks
• Metrics should include how much storage will tally take in case of on-chain reward calcualtion to fulfill this issue Q: How much storage we need to place the Tallys on-chain (For On-chain approach for reward calculations) #43
• Implement tests for consensus statistics collector subsystem
• Implement tests for the changes in the approval voting subsystem
• Publish data from consensus statistics collector subsystem through prometheus
• Implement Zombienet tests with Malus nodes to test no-shows stats collections

[P1sar]

https://github.com/ChainSafe/polkadot-sdk/pull/3/files

[P1sar]

paritytech/polkadot-sdk#9687

[P1sar]

• Currently we are missing tests
• metrics also to be done
• We are also missing Availability chunks Upload metrics, since there are some uncertainties we need to address and open questions how to collect them properly