Opportunity to improve JSON Logging

We have recently switched over to JSON (Structured) logging for Consul and for the most part things are pretty good, but we do still see instances of volatile data in the message that we would expect to be properties (which makes using log aggregation less effective

Example:
`{"@level":"info","@message":"serf: attempting reconnect to MOD-CPP-1690-ADD-csl2.control-plane-promoter :","@module":"agent.server.serf.wan","@timestamp":"2021-12-16T16:56:33.593775Z"}`

Here we would expect the message to be "attempting to reconnect" with properties with the values "serf", "MOD-CPP-1690-ADD-csl2.control-plane-promoter", and ":"

Another Example:
`grpc: addrConn.createTransport failed to connect to {control-plane-promoter-< 0 MOD-CPP-1689-ADD-csl1.control-plane-promoter }. Err :connection error: desc = "transport: Error while dialing dial tcp:0->:: connect: no route to host". Reconnecting`

So far these are the only two examples we've found so it's relatively minor but it's a nice opportunity for improvement

Thanks
Ian