improve -V/W output when kea is installed from pkgs

At this point kea-dhcp4 -V output may have two options:

• when installed from git:

2.5.2-git
git 7129fed942dd381d8946f5b43f5423b8d4ccab20
(and other stuff)

• when installed from tarball or pkg:

2.5.2
tarball

And this solution introduces some problems when we quickly try to debug reported issue, even with version reported we need to ask how it was installed, I would add 3rd way and when installed from pkg kea-dhcp4 -V would return:

2.5.2
isc20230630120747 (rpm)

this would require change in configure.ac and kea-packaging repo.