Clang/ClangTools: Separate custom diagnostic configs

Add a separate pool of custom diagnostic configs for the
ClangTools plugin. That is, the diagnostic configs in

  Menu: Tools > C++ > Code Model

are not shared anymore with the configs at

  Menu: Tools > Analyzer > ClangTools

On plugin initialization of ClangTools, move tidy/clazy related configs
to ClangTools.

Change-Id: Id06087a58b53e466a3d7bbac669550c5fbe9899d
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/clangtools/clangtoolsplugin.cpp

@@ -113,6 +113,10 @@ bool ClangToolsPlugin::initialize(const QStringList &arguments, QString *errorSt
     Q_UNUSED(arguments)
     Q_UNUSED(errorString)
 
+    // Import tidy/clazy diagnostic configs from CppTools now
+    // instead of at opening time of the settings page
+    ClangToolsSettings::instance();
+
     d = new ClangToolsPluginPrivate;
 
     ActionManager::registerAction(d->clangTool.startAction(), Constants::RUN_ON_PROJECT);