More detailed error messages in C++ nodes

[phil-opp]

The cxx crate that we use to bridge between Rust and C++ uses the Display implementation of errors. For eyre::Report errors, this means that only the outer context is printed, e.g. "failed to receive response". For debugging, it would be useful to use the Debug output instead, which prints the underlying causes as well.

To implement this, we could do a map_err(|e| eyre::eyre!("{e:?}")) call before returning to C++.