Add git-pseudo-version

[chenlujjj]

It can be used to print pesudo-version of go module of current repository.

[guenhter]

It seems like this is not exaclty what go defines as pseudo version:

https://go.dev/ref/mod#pseudo-versions

Each pseudo-version has three parts ....

[guenhter]

And isn't this be something which should go more into a go-module instead of the git-module?