kiwix-tools: init at 3.4.0

this provides the `kiwix-serve` tool asked for in
<https://github.com/NixOS/nixpkgs/issues/35009>,
but does not implement the systemd service requested.

package contents:
- bin/kiwix-manage
- bin/kiwix-search
- bin/kiwix-serve

tested by invoking `kiwix-serve` and connecting to it in a web browser:

```sh
nix build '.#kiwix-tools'
wget 'https://dumps.wikimedia.org/other/kiwix/zim/wikipedia/wikipedia_en_simple_all_mini_2022-11.zim'
./result/bin/kiwix-serve -p 1080 ./wikipedia_en_simple_all_mini_2022-11.zim
curl http://localhost:1080
```

pkgs/applications/misc/kiwix/default.nix

···
   meta = with lib; {
     description = "An offline reader for Web content";
     homepage = "https://kiwix.org";
-    license = licenses.gpl3;
+    license = licenses.gpl3Plus;
     platforms = platforms.linux;
     maintainers = with maintainers; [ ajs124 ];
   };

pkgs/applications/misc/kiwix/lib.nix

···
   meta = with lib; {
     description = "Common code base for all Kiwix ports";
     homepage = "https://kiwix.org";
-    license = licenses.gpl3;
+    license = licenses.gpl3Plus;
     platforms = platforms.linux;
     maintainers = with maintainers; [ colinsane ];
   };

pkgs/applications/misc/kiwix/tools.nix

···
+{ lib
+, fetchFromGitHub
+, icu
+, libkiwix
+, meson
+, ninja
+, pkg-config
+, stdenv
+}:
+
+stdenv.mkDerivation rec {
+  pname = "kiwix-tools";
+  version = "3.4.0";
+
+  src = fetchFromGitHub {
+    owner = "kiwix";
+    repo = "kiwix-tools";
+    rev = version;
+    sha256 = "sha256-r3/aTH/YoDuYpKLPakP4toS3OtiRueTUjmR34rdmr+w=";
+  };
+
+  nativeBuildInputs = [
+    meson
+    ninja
+    pkg-config
+  ];
+
+  buildInputs = [
+    icu
+    libkiwix
+  ];
+
+  meta = with lib; {
+    description = "Command line Kiwix tools: kiwix-serve, kiwix-manage, ...";
+    homepage = "https://kiwix.org";
+    license = licenses.gpl3Plus;
+    platforms = platforms.linux;
+    maintainers = with maintainers; [ colinsane ];
+  };
+}
+

pkgs/top-level/all-packages.nix

···
 
   kiwix = libsForQt5.callPackage ../applications/misc/kiwix { };
 
+  kiwix-tools = callPackage ../applications/misc/kiwix/tools.nix { };
+
   klayout = libsForQt5.callPackage ../applications/misc/klayout { };
 
   klee = callPackage ../applications/science/logic/klee (with llvmPackages_11; {