Add git-commit to the `git-credential-keepassxc -V`

[stdedos]

To avoid ambiguities in artifacts (especially for people like me that download "the latest and greatest", without waiting for official releases), it would be nice if the version string was instead:

$ git-credential-keepassxc -V
git-credential-keepassxc v0.8.2 (v0.8.2+8 8575367)

Or something equivalent to git describe --long --always (add --tags also if you do not want to use "annotated tags": https://git-scm.com/book/en/v2/Git-Basics-Tagging#_creating_tags)