wiggle: allow disable tracing in Wiggle-generated code (#5146)

Wiggle generates code that instruments APIs with tracing code. This is
handy for diagnosing issues at runtime, but when inspecting the output
of Wiggle, it can make the generated code difficult for a human to
decipher. This change makes tracing a default but optional feature,
allowing users to avoid tracing code with commands like `cargo expand
--no-default-features`. This should be no change for current crates
depending on `wiggle`, `wiggle-macro`, and `wiggle-generate`.

review: add 'tracing' feature to wasi-common

review: switch to using macro configuration parsing

Co-authored-by: Andrew Brown <andrew.brown@intel.com>

crates/wasi-common/src/snapshots/preview_1.rs

@@ -25,7 +25,7 @@ wiggle::from_witx!({
     // keeping that set the same in this macro and the wasmtime_wiggle / lucet_wiggle macros is
     // tedious, and there is no cost to having a sync function be async in this case.
     async: *,
-    wasmtime: false
+    wasmtime: false,
 });
 
 impl wiggle::GuestErrorType for types::Errno {