Problem

There are some string that come from backend and it is displayed to user. But we do not set localization for those strings.

trello: https://trello.com/c/Jp7S5kwh/3398-5-agama-add-support-for-translating-the-messages-from-the-d-bus-interface

Solution

Implement in Locale method to enlist all possible backend localization ( so far only for ruby based ones ) and allow to set localization. In other services have helper that will set initial localization (1) and also catch signal when it is changed (2).
As part of this PR also drop no longer used Language Service.

(1)

class Agama::DBus::FooService
...
      def start
        locale_client = Clients::Locale.new
        @ui_locale = UILocale.new(locale_client)
        export
      end
end

(2) see on_ui_locale_change

Testing

• Tested manually

Screenshots

Example localization in czech ( in czech is only data comming from dbus ):