Protocol refactoring

[Mallets]

A new version of the zenoh protocol is under development. The new version is expected to improve extensibility and flexibility allowing zenoh to effectively address a multitude of scenarios.

This issue is to keep track of the ongoing activities. It will be closed once the protocol is implemented, properly documented, and merged in the master branch.

To keep track of the ongoing work:

• [ ] Protocol implementation
• [ ] Protocol documentation

[Mallets]

The ongoing work can be monitored in the new-protocol branch.