fix: make wasm features implicit

[hanabi1224]

Description

This PR tries to make wasm-bindgen features implicit

Notes & open questions

Change checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• A changelog entry has been made in the appropriate crates

[elenaf9]

Thanks for the PR @hanabi1224.

I think this is a small improvement that would be nice to have. However, it is a breaking change in libp2p-swarm, which unfortunately requires us to also bump and release all libp2p protocols that depend on libp2p-swarm. This is overall quite painful and imo not worth it right now, especially because current users will already have enabled the wasm-bindgen feature.
I would delay this PR until the next required breaking change of libp2p-swarm.
cc @jxs

[dariusc93]

Since we will delay this, I will move this to draft for now.