Ref T99, use new icon names

* use icon id list from directory for performance
* some minor adjustments

src/blackmisc/aviation/airlineicaocode.h

@@ -25,6 +25,7 @@
 #include <QJsonObject>
 #include <QMetaType>
 #include <QString>
+#include <QSet>
 
 namespace BlackMisc
 {
@@ -236,6 +237,9 @@ namespace BlackMisc
             //! From our DB JSON
             static CAirlineIcaoCode fromDatabaseJson(const QJsonObject &json, const QString &prefix = QString());
 
+            //! The airline icon names (name only, not path)
+            static const QSet<int> &iconIds();
+
         private:
             QString m_designator;           //!< "DLH"
             QString m_iataCode;             //!< "LH"