firefox: put "unwrapped" into its name

I'm not certain about this, so I'm trying for firefox only.
Rationale: it might be confusing to see two firefox-${version} instances
in logs or paths, so I wanted to differentiate them.

pkgs/applications/networking/browsers/firefox/default.nix

@@ -19,7 +19,7 @@ assert stdenv.cc ? libc && stdenv.cc.libc != null;
 let
 
 common = { pname, version, sha256 }: stdenv.mkDerivation rec {
-  name = "${pname}-${version}";
+  name = "${pname}-unwrapped-${version}";
 
   src = fetchurl {
     url =