MINOR: mux-h1/trace: register a new trace source with its events

MINOR: mux-h1/trace: register a new trace source with its events

As for the mux h2, traces are now supported in the mux h1. All parts of the
multiplexer is covered by these traces. Events are splitted by categories (h1c,
h1s, stream, rx and tx) for a total of ~30 different events with 5 verboisty
levels.

In traces, the first argument is always a connection. So it is easy to get the
h1c (conn->ctx). The second argument is always a h1s. The third one is an HTX
message. Depending on the context it is the request or the response. In all
cases it is owned by a channel. Finally, the fourth argument is an integer
value. Its meaning depends on the calling context.