Build version based only on assets in source code

Currently, version is grabbed from the last tag in the git tree, this, however, doesn't work if you don't build from git repo, or you just pulled a shallow branch.

There are multiple ways how to solve it:
- metadata in `node/Cargo.toml`
- parse changelog
- add a file with this information

also if the source is not built from git repo, revision hash shouldn't be present I the version string