[locale] Add properties for language and LC codes

- we already had the human-readable status strings, but also want the
  actual code (particularly for being able to **update** the code
  from QML)

src/modules/locale/Config.cpp

@@ -288,6 +288,7 @@ Config::setLanguageExplicitly( const QString& language )
     m_selectedLocaleConfiguration.explicit_lang = true;
 
     emit currentLanguageStatusChanged( currentLanguageStatus() );
+    emit currentLanguageCodeChanged( currentLanguageCode() );
 }
 
 void
@@ -306,6 +307,7 @@ Config::setLCLocaleExplicitly( const QString& locale )
     m_selectedLocaleConfiguration.explicit_lc = true;
 
     emit currentLCStatusChanged( currentLCStatus() );
+    emit currentLCCodeChanged( currentLCCode() );
 }
 
 QString

src/modules/locale/Config.h

@@ -43,9 +43,13 @@ class Config : public QObject
     Q_PROPERTY( const CalamaresUtils::Locale::TZZone* currentLocation READ currentLocation WRITE setCurrentLocation
                     NOTIFY currentLocationChanged )
 
+    // Status are complete, human-readable, messages
     Q_PROPERTY( QString currentLocationStatus READ currentLocationStatus NOTIFY currentLanguageStatusChanged )
     Q_PROPERTY( QString currentLanguageStatus READ currentLanguageStatus NOTIFY currentLanguageStatusChanged )
     Q_PROPERTY( QString currentLCStatus READ currentLCStatus NOTIFY currentLCStatusChanged )
+    // Code are internal identifiers, like "en_US.UTF-8"
+    Q_PROPERTY( QString currentLanguageCode READ currentLanguageCode WRITE setLanguageExplicitly NOTIFY currentLanguageCodeChanged )
+    Q_PROPERTY( QString currentLCCode READ currentLCCode WRITE setLCLocaleExplicitly NOTIFY currentLCCodeChanged )
 
 public:
     Config( QObject* parent = nullptr );
@@ -103,11 +107,16 @@ public Q_SLOTS:
      */
     void setCurrentLocation( const CalamaresUtils::Locale::TZZone* location );
 
+    QString currentLanguageCode() const { return localeConfiguration().language(); }
+    QString currentLCCode() const { return localeConfiguration().lc_numeric; }
+
 signals:
     void currentLocationChanged( const CalamaresUtils::Locale::TZZone* location ) const;
     void currentLocationStatusChanged( const QString& ) const;
     void currentLanguageStatusChanged( const QString& ) const;
     void currentLCStatusChanged( const QString& ) const;
+    void currentLanguageCodeChanged( const QString& ) const;
+    void currentLCCodeChanged( const QString& ) const;
 
 private:
     /// A list of supported locale identifiers (e.g. "en_US.UTF-8")