Versioning for node-split

[pigmej]

Given the "only api integrations" we need to re-introduce versions to the APIs.

The current idea would be to have two separate versions served as:

• v2beta1.NodeService/Version
• v2beta1.SmesherService/Version

We split them because we may split the binaries even further in the future, so there will need to be two separate calls.

The version should return stuff similar to v1 API, so it should be a version (tag) and a commit.

Additionally after the backends are done we need to have some frontend integration for it too where based on the returned SmeshingService version proper frontend is served.