keepassxc: add firefox native messaging host file

When using a Firefox fork, upstream package relies on you entering the
browser user config path manually and writes the native messaging host
file to that path. It should be much more convenient to manage it in
Nix.

pkgs/applications/misc/keepassxc/default.nix

···
     wrapQtApp "$out/Applications/KeePassXC.app/Contents/MacOS/KeePassXC"
   '';
 
+  # See https://github.com/keepassxreboot/keepassxc/blob/cd7a53abbbb81e468efb33eb56eefc12739969b8/src/browser/NativeMessageInstaller.cpp#L317
+  postInstall = lib.optionalString withKeePassBrowser ''
+    mkdir -p "$out/lib/mozilla/native-messaging-hosts"
+    substituteAll "${./firefox-native-messaging-host.json}" "$out/lib/mozilla/native-messaging-hosts/org.keepassxc.keepassxc_browser.json"
+  '';
+
   buildInputs = [
     curl
     botan2

pkgs/applications/misc/keepassxc/firefox-native-messaging-host.json

···
+{
+    "name": "org.keepassxc.keepassxc_browser",
+    "description": "KeePassXC integration with native messaging support",
+    "path": "@out@/bin/keepassxc-proxy",
+    "type": "stdio",
+    "allowed_extensions": [
+        "[e-mail]"
+    ]
+}

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

···
 , browserpass, gnome-browser-connector, uget-integrator, plasma5Packages, bukubrow, pipewire
 , tridactyl-native
 , fx-cast-bridge
+, keepassxc
 , udev
 , libkrb5
 , libva
···
           ++ lib.optional (cfg.enableUgetIntegrator or false) uget-integrator
           ++ lib.optional (cfg.enablePlasmaBrowserIntegration or false) plasma5Packages.plasma-browser-integration
           ++ lib.optional (cfg.enableFXCastBridge or false) fx-cast-bridge
+          ++ lib.optional (cfg.enableKeePassXC or false) keepassxc
           ++ extraNativeMessagingHosts
         ;
       libs =   lib.optionals stdenv.isLinux [ udev libva mesa libnotify xorg.libXScrnSaver cups pciutils ]