Clang: Make clazy UI more fine-grained

...so that specific checks can be enabled/disabled.

This replaces the level radio buttons in Tools > Options > C++ > Code
Model > "Manage..." > Tab: Clazy.

Task-number: QTCREATORBUG-21120
Change-Id: If468d79d3c309b287b4105d83ac31f0b1489c71c
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/cpptools/cppcodemodelsettings.h

@@ -61,6 +61,9 @@ public:
     ClangDiagnosticConfigs clangCustomDiagnosticConfigs() const;
     void setClangCustomDiagnosticConfigs(const ClangDiagnosticConfigs &configs);
 
+    bool enableLowerClazyLevels() const;
+    void setEnableLowerClazyLevels(bool yesno);
+
     PCHUsage pchUsage() const;
     void setPCHUsage(PCHUsage pchUsage);
 
@@ -84,6 +87,7 @@ private:
     int m_indexerFileSizeLimitInMB = 5;
     ClangDiagnosticConfigs m_clangCustomDiagnosticConfigs;
     Core::Id m_clangDiagnosticConfigId;
+    bool m_enableLowerClazyLevels = true; // For UI behavior only
 };
 
 } // namespace CppTools