ClangFormat: Use relevant settings for each file

Existing Clang Format settings may not follow the
project/global pattern but can be expected to be used
for the indentation/formatting.

So let's proceed with UI for global/project settings
but use global settings only if there's no configuration
found for the current file.

Change-Id: I87c25ab3feb7e2e3deb0290848088657783cf972
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/plugins/clangformat/clangformatconfigwidget.cpp

@@ -139,7 +139,7 @@ void ClangFormatConfigWidget::initialize()
 
         connect(m_ui->createFileButton, &QPushButton::clicked,
                 this, [this]() {
-            createStyleFileIfNeeded(m_project->projectDirectory(), false);
+            createStyleFileIfNeeded(false);
             initialize();
         });
         return;
@@ -160,8 +160,7 @@ void ClangFormatConfigWidget::initialize()
                     tr("Current project has its own .clang-format file "
                        "and can be configured in Projects > Clang Format."));
         }
-        const QString settingsDir = Core::ICore::userResourcePath();
-        createStyleFileIfNeeded(Utils::FileName::fromString(settingsDir), true);
+        createStyleFileIfNeeded(true);
         m_ui->applyButton->hide();
     }