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/clangformat/clangformatconfigwidget.cpp

@@ -201,11 +201,6 @@ void ClangFormatConfigWidget::showCombobox()
     m_ui->indentingOrFormatting->insertItem(indentIndex(), tr("Indenting only"));
     m_ui->indentingOrFormatting->insertItem(formatIndex(), tr("Full formatting"));
 
-    connect(m_ui->indentingOrFormatting, QOverload<int>::of(&QComboBox::currentIndexChanged), this, [this](int) {
-        if (m_project)
-            apply();
-    });
-
     if (ClangFormatSettings::instance().formatCodeInsteadOfIndent())
         m_ui->indentingOrFormatting->setCurrentIndex(formatIndex());
     else