ClangCodeModel: Add clangd-based document locator filter

Change-Id: I2811be80e740cacf57eccd19e47560af746ad0c1
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangdclient.h

@@ -79,6 +79,9 @@ public:
     void enableTesting();
     bool testingEnabled() const;
 
+    static QString displayNameFromDocumentSymbol(LanguageServerProtocol::SymbolKind kind,
+                                                 const QString &name, const QString &detail);
+
 signals:
     void indexingFinished();
     void foundReferences(const QList<Core::SearchResultItem> &items);