feat(metrics): add metrics in chain-listener [NET-806]

[kmd-fl]

Description

Add some metrics to the ChainListener module.

Proposed Changes

Add a pack of metrics:

pub struct ChainListenerMetrics {
    // how many request Nox sends to ccp
    ccp_requests_total: Counter,
    // how many success replies Nox receives from ccp
    // an error is either error from ccp or connection errors
    ccp_replies_total: Counter,
    // how long we wait for a reply from ccp
    ccp_request_duration_msec: Histogram,
    // how many proofs we submitted
    cpp_proofs_submitted: Counter,
    // how many proofs we failed to submit
    cpp_proofs_submit_failed: Counter,
    // how many proofs transaction are ok
    ccp_proofs_tx_success: Counter,
    // how many proofs transaction are failed
    ccp_proofs_tx_failed: CounterWithExemplar<TxLabel>,
    // How many blocks we have received from the newHead subscription
    blocks_seen: CounterWithExemplar<BlockLabel>,
    // How many block we manage to process while processing the block
    blocks_processed: Counter,
}

Additional Notes

We were discussing some refactoring, and I did the tiniest amount of refactoring, but I think we should do it in a separate PR.

[linear]

NET-806 Add metrics to ChainListener

[justprosh]

Overall very cool! Thx very much for explanatory comments 🙏🙏🙏

[folex]

nice!

[folex]

shouldn't this be a gauge with a block number?

[folex]

and this, too