We no longer rely on git tags and git describe output, since it's
hard to reliably select the correct tag eg for minor releases.
We might use them again in future for dev builds, but it requires
adding git describe --match support to githash. For now,
* Program name, OS and architecture are always shown.
* The package version is always shown.
* If there is git info at build time, the latest commit hash and commit date are shown.
Example outputs:
A homebrew binary, not built in git repo: hledger-ui 1.24, mac-aarch64
A CI release build, built in git repo: hledger 1.24.1-g455b35293-20211210, mac-x86_64
API changes:
* new type synonyms ProgramName, PackageVersion, VersionString
* versionStringForProgname -> versionString with extra argument
* versionStringFor -> versionStringWith with extra argument
1ef8f329c6