Core: Remove PagedSettings again

Turned out to create a too strict tie between settings and
settings pages, we are more flexible with delaying/avoiding
initialization without these.

Change-Id: I948af675e29c7da34bfccd490c1c1b999923f279
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/coreplugin/dialogs/ioptionspage.cpp

@@ -314,12 +314,4 @@ const QList<IOptionsPageProvider *> IOptionsPageProvider::allOptionsPagesProvide
     return g_optionsPagesProviders;
 }
 
-// PagedSettings
-
-PagedSettings::PagedSettings()
-{
-    setSettings(this);
-    setAutoApply(false);
-}
-
 } // Core

src/plugins/coreplugin/dialogs/ioptionspage.h

@@ -120,10 +120,4 @@ protected:
     Utils::FilePath m_categoryIconPath;
 };
 
-class CORE_EXPORT PagedSettings : public Utils::AspectContainer, public IOptionsPage
-{
-public:
-    PagedSettings();
-};
-
 } // namespace Core