GetMosVersion returns this binary's version, or "latest" if it's not a release build.

GetMosVersionSuffix returns an empty string if mos version is "latest"; otherwise returns the mos version prepended with a dash, like "-1.6".

GetUbuntuPackageName parses given build id string, and if it looks like a debian build id, returns either "latest" or "release".

Returns whether the build id looks like the mos was built in some distro environment (like, ubuntu or brew), and thus it shouldn't update itself.