Due to cargo's feature unification, a full build of our workspace doesn't actually check whether the examples compile as standalone projects.
We add a new CI check that iterates through all crates in the `examples/` directory and runs a plain `cargo check` on them. Any failure is bubbled up via `set -e`, thus failing CI in case one of the `cargo check` commands fails.
To fix the current failures, we construct a simple TCP transport everywhere where we were previously using `development_transport`. That is because `development_transport` requires `mplex` which is now deprecated.
Related #3657.
Related #3809.
Pull-Request: #3811.
