test-utilities: version test

Extract 'version test' to a reusable test utility as discussed in
https://github.com/NixOS/nixpkgs/pull/119636#issuecomment-826137021 and

pkgs/applications/misc/hello/default.nix

@@ -1,4 +1,9 @@
-{ lib, stdenv, fetchurl }:
+{ lib
+, stdenv
+, fetchurl
+, testVersion
+, hello
+}:
 
 stdenv.mkDerivation rec {
   pname = "hello";
@@ -11,6 +16,9 @@ stdenv.mkDerivation rec {
 
   doCheck = true;
 
+  passthru.tests.version =
+    testVersion { package = hello; };
+
   meta = with lib; {
     description = "A program that produces a familiar, friendly greeting";
     longDescription = ''