QmlDebug: Simplify logic to find the source file for a stack frame

Get rid of custom logic to handle shadow builds (which didn't work
anyway if the qml files are from a different directory than expected).
Instead, just search for the file name in the list of files from the
project.

Reviewed-by: Christiaan Janssen

src/plugins/debugger/debuggerstartparameters.h

@@ -92,8 +92,9 @@ public:
     // Used by Qml debugging.
     QString qmlServerAddress;
     quint16 qmlServerPort;
-    QString projectBuildDir;
-    QString projectDir;
+    QString projectSourceDirectory;
+    QString projectBuildDirectory;
+    QStringList projectSourceFiles;
 
     QString qtInstallPath;
     // Used by remote debugging.