Ship our FontConfig configuration with the browser

On Linux we have a nice functionality to reset the font configuration.

However, some users might skip it (e.g., because they don't start the browser in the correct way, or because it's a 3rd party repackage that is missing that thing).

I found that we could use a nice function to check if the user is using our configuration:

  FcChar8 *path = FcConfigFilename(nullptr);
  printf("The path is: %s\n", path); // e.g., /home/piero/Tor/tor-browser/.binaries/dev/Browser/fontconfig/fonts.conf
  FcStrFree(path);

So, we could add a warning message (e.g., in a notification bar?) to tell that we suspect the user isn't using our config and that their fingerprint will likely be different from other users.

Is a notification good enough for that? What message could we display?