This pull request adds a new "mesage_type" label to the send/recv bytes metrics calculated in the p2p code.
Below is a snippet of the updated metrics that includes the updated label:
```
tendermint_p2p_peer_receive_bytes_total{chID="32",chain_id="ci",message_type="consensus_HasVote",peer_id="2551a13ed720101b271a5df4816d1e4b3d3bd133"} 652
tendermint_p2p_peer_receive_bytes_total{chID="32",chain_id="ci",message_type="consensus_HasVote",peer_id="4b1068420ef739db63377250553562b9a978708a"} 631
tendermint_p2p_peer_receive_bytes_total{chID="32",chain_id="ci",message_type="consensus_HasVote",peer_id="927c50a5e508c747830ce3ba64a3f70fdda58ef2"} 631
tendermint_p2p_peer_receive_bytes_total{chID="32",chain_id="ci",message_type="consensus_NewRoundStep",peer_id="2551a13ed720101b271a5df4816d1e4b3d3bd133"} 393
tendermint_p2p_peer_receive_bytes_total{chID="32",chain_id="ci",message_type="consensus_NewRoundStep",peer_id="4b1068420ef739db63377250553562b9a978708a"} 357
tendermint_p2p_peer_receive_bytes_total{chID="32",chain_id="ci",message_type="consensus_NewRoundStep",peer_id="927c50a5e508c747830ce3ba64a3f70fdda58ef2"} 386
```