Move filename line split into Utils::Link

Since we already have a container for file path, line and column move
the parse function there.

Change-Id: I5d0d97d271c5aaeb618e1a303b02cc6514e94e81
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/plugins/coreplugin/coreplugin.h

@@ -77,8 +77,6 @@ public slots:
 private slots:
     void testVcsManager_data();
     void testVcsManager();
-    void testSplitLineAndColumnNumber();
-    void testSplitLineAndColumnNumber_data();
     // Locator:
     void test_basefilefilter();
     void test_basefilefilter_data();