MinimizableInfoBars: Remove dependency on CppToolsSettings

They were only used in the info bars, so move them there.

Change-Id: I584c98c70d1db2a5b741842da9d629469f0de73c
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/cppeditor/cppeditordocument.cpp

@@ -128,6 +128,8 @@ CppEditorDocument::CppEditorDocument()
     connect(&m_parseContextModel, &ParseContextModel::preferredParseContextChanged,
             this, &CppEditorDocument::reparseWithPreferredParseContext);
 
+    m_minimizableInfoBars.setSettingsGroup(Constants::CPPEDITOR_SETTINGSGROUP);
+
     // See also onFilePathChanged() for more initialization
 }