ClangFormat: Start to use new file management

- Indenter uses .clang-format file from a dir of
editing file or from a parent dir. If there is no
such file then indenter starts to use file from a dir
with the name current CodeStyle settings.
- Test fixed

ToDo: Add file absentness processing in case of import

Change-Id: If09ef0c598899856b948c214e524bcfd5dad76e2
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/clangformat/clangformatindenter.cpp

@@ -40,11 +40,6 @@ ClangFormatIndenter::ClangFormatIndenter(QTextDocument *doc)
     : ClangFormatBaseIndenter(doc)
 {}
 
-FormatStyle ClangFormatIndenter::styleForFile() const
-{
-    return ClangFormat::styleForFile(m_fileName);
-}
-
 bool ClangFormatIndenter::formatCodeInsteadOfIndent() const
 {
     return ClangFormatSettings::instance().formatCodeInsteadOfIndent();