Utils: Wrap various file system iteration flags and filters

... into a single class.

This makes passing them around as a whole easier, and opens a path
to have "generic" filters in form of a lambda or such.

Change-Id: Ibf644b2fedcf0f1a35258030710afff8f5873f88
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/remotelinux/filesystemaccess_test.cpp

@@ -114,8 +114,7 @@ void FileSystemAccessTest::testDirStatuses()
             }
             return false;
         },
-        {"test"},
-        QDir::Files);
+        {{"test"}, QDir::Files});
 
     QVERIFY(fileExists);
     QVERIFY(testFilePath.removeFile());