Add css class to hyprland language module of short_name language code

[dimti]

Accordinally to sway language module #1628.
This added similaral functionality for hyprland language module.

And in style.css poissble now, as demo example - separate styles for any keyboard layout:

#language
{
  color:#d08770;
}

#language.en
{
  color:#6114dc;
}

[winkelnp]

Testing this on my system, this doesn't update the style context when the layout is changed while waybar is running, you'd need to add a similar thing in onEvent around the layout_ = line

[dimti]

@winkelnp Okay. Im add both in init method and to onEvent. Sorry for the untested un first commit