…ealliance#9262)

* wit-bindgen: Don't trace values containing lists by default.

`list` values in Wit interfaces can represent things like HTTP bodies
which can be very large. To enable tracing without spamming logfiles
with all this data, put printing of values containing `list`s behind
a separate `verbose_tracing` option.

This is a coarse-grained approach; but it seems like a pretty good
default for tracing, and enabling full tracing when one needs it is
straightforward.

In the future, we may want to refine the option by implementing
the `Valuable` trait and using `tracing::field::valuable`, which
could allow us to do things like print non-`list` fields of records
that otherwise contain `list`s.

* Use `option_type_contains_lists` more.

* Hook up `verbose_tracing` to the macro.

* Update expected outputs for tests.