logic: reimplemented task system to abort ast visiting

* reimplemented interrupting TaskParseCxx by adding a listener for the MessageInterruptTask and returning a failure status code on update. This cancels the parent sequence task which results in the indexed items not getting inserted into the persistent storage
* removed the capability for interrupting from TaskScheduler
* changed task system to be closer to the standard behavior tree implementation
* changed task system to accommodate the 3 status return types: Running, Success and Failure
* made TaskGroupSequential fail once a member task fails
* made TaskGroupParallel fail once a member task fails
* split TaskParse... into one task for indexing and one task for injecting
* added TaskRunner that handles updating and resetting the managed task
* fixed numbers that are shown as parsed file count in indexing ui
* fixed deadlock that originated from interaction between TaskScheduler and MessageQueue (one thread wanted to destroy a message listener on a task while the other one wanted to send as message as a task)

src/lib/data/IntermediateStorage.h

@@ -14,6 +14,8 @@ public:
 	IntermediateStorage();
 	virtual ~IntermediateStorage();
 
+	void clear();
+
 	virtual Id addFile(const std::string& name, const std::string& filePath, const std::string& modificationTime);
 	virtual Id addNode(int type, const std::string& serializedName, int definitionType);
 	virtual Id addEdge(int type, Id sourceId, Id targetId);
@@ -56,8 +58,6 @@ private:
 	std::vector<StorageCommentLocation> m_commentLocations;
 	std::vector<StorageError> m_errors;
 
-	std::unordered_map<Id, Id> m_nodeIdsToMemberEdgeIds;
-
 	Id m_nextId;
 };