Try to call git from the path in the VersionUpdater without searching for specific locations

[SirePi]

Summary

As of today, the VersionUpdater tool has a couple of hardcoded paths where it looks for the git executable to perform its functions.
Probably it would make sense to have a first go for the PATH bound git.exe, without looking in other folders first.

[Barsonax]

This would be a nice improvement. I think however that we would also solve this (and other executable dependencies) if we moved to more modern build tooling: #810