Add ability to show current variant and current keyboard layout separately

[roguh]

Hello, I'd like it if this tool had options for showing the keyboard layout and variant separately, e.g. us and intl. For example:

$ xkb-switch -a
intl
$ xkb-switch -b
us
$ xkb-switch -p
us(intl)

[roguh]

Right now, I'm splitting the output on "(" to get the layout and variant as separate components.