Fmaste/network mux

[fmaste]

Description

reasonably detailed description of the pull request

Checklist

Quality

• Commit sequence makes sense and have useful messages, see ref.
• New tests are added and existing tests are updated.
• Self-reviewed the PR.

Maintenance

• Linked an issue or added the PR to the current sprint of ouroboros-network project.
• Added labels.
• Updated changelog files.
• The documentation has been properly updated, see ref.

[crocodile-dentist]

@coot should we make this a separate package eg. network-mux-trace?

[coot]

I'd move the library to cardano-diffusion:network-mux-trace, there a trace-dispatcher as s dependency is fine.