Ref T660, utility functions

* check if model is in path
* addAsValidOrInvalidModel
* set corresponding simulator for validation
* display validation of empty model set

src/blackmisc/simulation/aircraftmodel.h

@@ -457,6 +457,9 @@ namespace BlackMisc
             //! Directory path if any
             QString getFileDirectoryPath() const;
 
+            //! Is the file in the give path
+            bool isInPath(const QString &path, Qt::CaseSensitivity cs) const;
+
             //! File name
             void setFileName(const QString &fileName) { m_fileName = fileName; }