Clang: Add tooltip action to remove specific warnings/checks

...from the diagnostic configuration.

If no custom diagnostic configuration is set in Projects Mode > Clang,
one is created and set for the current project. Otherwise the current
custom diagnostic set in the project settings is modified.

Change-Id: I5c48280c90f0e807e7333122d504dda302a8b0a9
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/clangcodemodel/clangutils.h

@@ -72,6 +72,23 @@ QString diagnosticCategoryPrefixRemoved(const QString &text);
 
 void generateCompilationDB(::Utils::FileName projectDir, CppTools::ProjectInfo projectInfo);
 
+class DiagnosticTextInfo
+{
+public:
+    DiagnosticTextInfo(const QString &text);
+
+    QString textWithoutOption() const;
+    QString option() const;
+    QString category() const;
+
+    static bool isClazyOption(const QString &option);
+    static QString clazyCheckName(const QString &option);
+
+private:
+    const QString m_text;
+    const int m_squareBracketStartIndex;
+};
+
 namespace Text {
 
 template <class CharacterProvider>