ClangFormat: Replace checks widget with editor

The existing approach utilizing the widget poses maintenance
challenges, primarily due to the dynamic nature of clang-format
settings across versions. The widget necessitates regeneration
for each new version, and compatibility issues arise when users
have different clang-format versions on their devices.

The updated solution adopts an Editor integrated with a yaml
language server, offering the ability to highlight and provide
code completion for the .clang-format file. This resolves the
widget regeneration issue and ensures compatibility with various
clang-format versions.

- Replaced the checks widget with an editor
- Introduced a line for yaml language server schema
in .clang-format files to enable autocompletion.
ToDo: Enhance schema accessibility without relying on this line.
- Added Ctrl+Space shortcut for autocompletion
- Added Ctrl+S shortcut for saving
- Eliminated outdated logic related to the checks widget
- Fixed copying and removal of clang-format settings

Change-Id: I2e3fbf19abe2f4df031f6ba5faffd47e07274346
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/clangformat/clangformatbaseindenter.cpp

@@ -539,6 +539,7 @@ public:
 
     clang::format::FormatStyle customSettingsStyle(const FilePath &fileName) const;
     ICodeStylePreferences *m_overriddenPreferences = nullptr;
+    clang::format::FormatStyle m_overriddenStyle = clang::format::getNoStyle();
 };
 
 ClangFormatBaseIndenter::ClangFormatBaseIndenter(QTextDocument *doc)
@@ -870,6 +871,9 @@ const clang::format::FormatStyle &ClangFormatBaseIndenterPrivate::styleForFile()
 {
     static const milliseconds cacheTimeout = getCacheTimeout();
 
+    if (!(m_overriddenStyle == clang::format::getNoStyle()))
+        return m_overriddenStyle;
+
     QDateTime time = QDateTime::currentDateTime();
     if (m_cachedStyle.expirationTime > time && !(m_cachedStyle.style == clang::format::getNoStyle()))
         return m_cachedStyle.style;
@@ -907,4 +911,9 @@ void ClangFormatBaseIndenter::setOverriddenPreferences(ICodeStylePreferences *pr
     d->m_overriddenPreferences = preferences;
 }
 
+void ClangFormatBaseIndenter::setOverriddenStyle(const clang::format::FormatStyle &style)
+{
+    d->m_overriddenStyle = style;
+}
+
 } // namespace ClangFormat