Output of tracing-subscribe is verbose and difficult to read

I ran Wasmtime with `WASMTIME_LOG=wasmtime_wasi` just now and it looks like:

Part of this is that my terminal screen isn't super wide but even on the widest setting

I find this difficult to read.

I find that there's a ton of output per line. For example one log line looks like:

```
2023-11-03T15:56:46.567847Z \
TRACE \
wit-bindgen export{module="wasi:http/incoming-handler@0.2.0-rc-2023-11-05" function="handle"}:wit-bindgen \
import{module="streams" function="[method]input-stream.read"}: \
wasmtime_wasi::preview2::bindings::wasi::io::streams:
```

which takes up basically the entire screen before getting to the actual relevant message:

```
call self_=Resource { rep: 7, state: "borrow" } len=16384
```

Aesthetically I also find the highlighting quite confusing to read and sift through. I don't know if this has to do with my OS, terminal emulator, or what.