[libcalamares] Access list of locale Ids

- Make it easier to obtain locale-ids (from CALAMARES_TRANSLATION_LANGUAGES)
   so avoid splitting that string multiple times.

src/libcalamares/locale/LabelModel.cpp

@@ -29,6 +29,7 @@ namespace Locale
 
 LabelModel::LabelModel( const QStringList& locales, QObject* parent )
     : QAbstractListModel( parent )
+    , m_localeIds( locales )
 {
     Q_ASSERT( locales.count() > 0 );
     m_locales.reserve( locales.count() );
@@ -132,7 +133,7 @@ LabelModel::find( const QString& countryCode ) const
 LabelModel*
 availableTranslations()
 {
-    static LabelModel* model = new LabelModel( QString( CALAMARES_TRANSLATION_LANGUAGES ).split( ';' ) );
+    static LabelModel* model = new LabelModel( QStringLiteral( CALAMARES_TRANSLATION_LANGUAGES ).split( ';' ) );
     return model;
 }
 

src/libcalamares/locale/LabelModel.h

@@ -54,6 +54,9 @@ public:
      */
     const Label& locale( int row ) const;
 
+    /// @brief Returns all of the locale Ids (e.g. en_US) put into this model.
+    const QStringList& localeIds() const { return m_localeIds; }
+
     /** @brief Searches for an item that matches @p predicate
      *
      * Returns the row number of the first match, or -1 if there isn't one.
@@ -67,6 +70,7 @@ public:
 
 private:
     QVector< Label > m_locales;
+    QStringList m_localeIds;
 };
 
 /** @brief Returns a model with all available translations.