This continues the push of plumbing contexts through tendermint. I
attempted to find all goroutines in the production code (non-test) and
made sure that these threads would exit when their contexts were
canceled, and I believe this PR does that.
The main (and minor) win of this PR is that the transport is fully the
responsibility of the router and the node doesn't need to be responsible for its lifecylce.
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
```
This code hasn't been battle tested, and seems to have grown
increasingly flaky int tests. Given our general direction of reducing
queue complexity over the next couple of releases I think it makes
sense to remove it.
A few notes:
- this is not all the deletion that we can do, but this is the most
"simple" case: it leaves in shims, and there's some trivial
additional cleanup to the transport that can happen but that
requires writing more code, and I wanted this to be easy to review
above all else.
- This should land *after* we cut the branch for 0.35, but I'm
anticipating that to happen soon, and I wanted to run this through
CI.
I put this error log in here because I thought it might be a helpful indicator to see when a reactor sends a message to a peer that doesn't have that channel open but it turns out this is happening all the time and it's kind of annoying
