logic: rewrote messages handling token activation for correct restoring on undo

* saving search query to undo stack with MessageSearch
* saving node and edge with name to undo stack with MessageActivateNode and MessageActivateEdge
* added FeatureController that handels distribution of MessageActivateTokens
* clearing views when refreshing or changing project
* clearing undo stack when changing project
* added StorageCache derived from StorageAccessProxy

src/lib/utility/utilityString.h

@@ -29,6 +29,7 @@ namespace utility
 	std::deque<std::string> tokenize(const std::deque<std::string>& list, char delimiter);
 	std::deque<std::string> tokenize(const std::deque<std::string>& list, const std::string& delimiter);
 
+	std::string substrBefore(const std::string& str, char delimiter);
 	std::string substrAfter(const std::string& str, char delimiter);
 
 	bool isPrefix(const std::string& prefix, const std::string& text);