CMakePM: Add policy support for help and code completion

Change-Id: I82d291639fe890602bba61eded9d1dfd7d38ca41
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/cmakeprojectmanager/cmakeeditor.cpp

@@ -78,6 +78,8 @@ void CMakeEditor::contextHelp(const HelpCallback &callback) const
             return "prop_test/";
         if (m_keywords.properties.contains(word))
             return "prop_gbl/";
+        if (m_keywords.policies.contains(word))
+            return "policy/";
 
         return "unknown/";
     };