Language widget need to have mode/language_mode option

[igs-shihchiehchou]

What is the request?

I need language mode/language_mode in Language widget options for label.

Why is it useful?

It tells which mode I'm currently using. Without having this, it will require to hit the keyboard many time just to check which mode I'm currently use. Or use mouse to click in language widget which is not very ideal.

How could it be implemented?

I don't actually know how to implement this, but I can give a direction:
There is a section after "Chinese (Traditional)" in image below, it shows "- US keyboard" and this is what I'm looking for but this only shows in context menu. Also "- US keyboard" might be too long to display, it also needs a short version.

The setting should looks like this:

# short
label: "{lang[language_code]}-{lang[country_code]} ({lang[language_mode]})"
# full
label: "{lang[language_code]}-{lang[country_code]} - {lang[language_mode_full]}"

Additional context

Thanks