Add example projects mainly as documentation of Gorums features

[meling]

We should add more projects to the examples folder. We can showcase the per-node-argument functions, used in recstore and we can showcase how we can implement Byzantine protocols with cryptographic keys in the quorum spec, as in byzq. We could also add the raft project as an example. It would be interesting to confirm that current version of Gorums solves the issue we had in the Raft project with quorum calls sometimes becoming unordered due to concurrency.

Adding these will require some work since these older projects are not "complete" and up-to-date (don't even have go.mod) and may require substantial testing.