Autotest: Keep track of generating framework in TestTreeItem

... and TestConfiguration. This allows dropping code that
reconstruct framework ids and framework lookup by id.

Change-Id: I0bb1e6e135376e21f96b9fab7971aa097787e483
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/autotest/qtest/qttestframework.cpp

@@ -36,9 +36,10 @@ ITestParser *QtTestFramework::createTestParser()
     return new QtTestParser(this);
 }
 
-TestTreeItem *QtTestFramework::createRootNode() const
+TestTreeItem *QtTestFramework::createRootNode()
 {
     return new QtTestTreeItem(
+                this,
                 QCoreApplication::translate("QtTestFramework",
                                             QtTest::Constants::FRAMEWORK_SETTINGS_CATEGORY),
                 QString(), TestTreeItem::Root);