ClangFormat: Fix unsaving properties for global settings

- Fixed behavior "Formatting mode" combobox settings isn't
saved after pressing "Ok" button when no one project is
open. Now it works as expected, settings save after press
"Ok" button.
- Added additional applying interface for ICodeStylePreferenceFactory
which allows pass-through apply call from dialog to the editor.

Note: it doesn't work with read-only code style profiles

Change-Id: If4f0c85e3105550db4ffd9860e94b678f0d9b386
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/cppeditor/cppcodestylesettingspage.cpp

@@ -97,7 +97,7 @@ static void applyRefactorings(QTextDocument *textDocument, TextEditorWidget *edi
 // ------------------ CppCodeStyleSettingsWidget
 
 CppCodeStylePreferencesWidget::CppCodeStylePreferencesWidget(QWidget *parent)
-    : QWidget(parent),
+    : TextEditor::CodeStyleEditorWidget(parent),
       m_ui(new Ui::CppCodeStyleSettingsPage)
 {
     m_ui->setupUi(this);
@@ -363,9 +363,17 @@ void CppCodeStylePreferencesWidget::addTab(CppCodeStyleWidget *page, QString tab
     connect(this, &CppCodeStylePreferencesWidget::tabSettingsChanged,
             page, &CppCodeStyleWidget::setTabSettings);
 
+    connect(this, &CppCodeStylePreferencesWidget::applyEmitted,
+            page, &CppCodeStyleWidget::apply);
+
     page->synchronize();
 }
 
+void CppCodeStylePreferencesWidget::apply()
+{
+    emit applyEmitted();
+}
+
 // ------------------ CppCodeStyleSettingsPage
 
 CppCodeStyleSettingsPage::CppCodeStyleSettingsPage()