p2p: we encode bitswap messages too much

[Arqu]

    > So what was wrong before?

The counters were in the encode/decode functions which skewed results as we encode a lot more than we actually send.

Originally posted by @Arqu in https://github.com/n0-computer/iroh/issues/374#issuecomment-1285326219

Last test it was about 1-2 Gbps encoded for 1-3 Mbps of traffic.