ClangTools: Make file selection dialog searchable/filterable

Allow filtering for open and edited documents.
Add also search functionality (triggerable by e.g. Ctrl+F).

Change-Id: Ib41400abfd3b81371afddd56b88ff1b9bf8b9bcd
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/clangtools/clangtool.h

@@ -88,7 +88,7 @@ public:
                      QString *errorMessage) const;
 
     FileInfos collectFileInfos(ProjectExplorer::Project *project,
-                               FileSelection fileSelection) const;
+                               FileSelection fileSelection);
 
     // For testing.
     QSet<Diagnostic> diagnostics() const;
@@ -112,6 +112,9 @@ private:
     void initDiagnosticView();
     void loadDiagnosticsFromFiles();
 
+    FileInfoProviders fileInfoProviders(ProjectExplorer::Project *project,
+                                        const FileInfos &allFileInfos);
+
     ClangToolsDiagnosticModel *m_diagnosticModel = nullptr;
     QPointer<Debugger::DetailedErrorView> m_diagnosticView;