AutoTest: Consolidate common functionality

While at it remove unused code path.

Change-Id: I15dff61131c5f3c9301cd733e1c8b92bd848f084
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/autotest/quick/quicktestconfiguration.h

@@ -38,11 +38,6 @@ public:
                                    QProcess *app) const override;
     QStringList argumentsForTestRunner(QStringList *omitted = nullptr) const override;
     Utils::Environment filteredEnvironment(const Utils::Environment &original) const override;
-    void setUnnamedOnly(bool unnamedOnly);
-    bool unnamedOnly() const { return m_unnamedOnly; }
-
-private:
-    bool m_unnamedOnly = false;
 };
 
 } // namespace Internal