devel/git-who: new port: Git blame for file trees

Unlike git blame, which can tell you who wrote a line of code, git-who tells
you the people responsible for entire components or subsystems in a codebase.
You can think of git-who sort of like git blame but
for file trees rather than individual files.

WWW: https://github.com/sinclairtarget/git-who

PR: 286146
Reported by: Yusuf Yaman <nxjoseph@protonmail.com> (new maintainer)