QDS-14390 Ignore comment lines in the qmlproject file

Closes QDS-14390

src/designviewer.cpp

@@ -112,7 +112,9 @@ void DesignViewer::parseQmlprojectFile(const QString &fileName,
         return;
     }
 
-    const QString text = QString::fromUtf8(file.readAll());
+    // Regular expression to remove lines starting with //
+    QRegularExpression commentRegExp("^\\s*//.*$", QRegularExpression::MultilineOption);
+    const QString text = QString::fromUtf8(file.readAll()).remove(commentRegExp);
 
     const QRegularExpression mainFileRegExp("mainFile:\\s*\"(.*)\"");
     const QRegularExpressionMatch mainFileMatch = mainFileRegExp.match(text);
@@ -133,7 +135,7 @@ void DesignViewer::parseQmlprojectFile(const QString &fileName,
     const QRegularExpressionMatch qt6ProjectMatch = qt6ProjectRegExp.match(text);
     if (!qt6ProjectMatch.hasMatch())
     {
-        qWarning() << "This is not a Qt6 project.\nQt5 projects might work, but they are not "
+        qWarning() << "This is not a Qt6 project.Qt5 projects might work, but they are not "
                       "officially supported.";
     }