Add string sanitization to property description

include/openspace/properties/property.h

@@ -465,7 +465,7 @@ public:
      *
      * \return The metadata information text for the property
      */
-    virtual std::string generateMetaDataJsonDescription() const;
+    std::string generateMetaDataJsonDescription() const;
 
     /**
      * Creates the information that is specific to each subclass of Property%s. If a
@@ -530,6 +530,9 @@ private:
 #endif
 };
 
+/// This function sanitizes an incoming string for JSON control characters
+std::string sanitizeString(const std::string& str);
+
 } // namespace openspace::properties
 
 #endif // __OPENSPACE_CORE___PROPERTY___H__