* 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)
* Added DialogView with QtDialogView implementation to handle information dialogs
* Implemented QtIndexingDialog class that covers all different dialogs for indexing
* Directly communicate with DialogView from Prpject and all Tasks involved in indexing
* Block QtMainWindow UI while indexing
* Fixed CPPSqliteException being thrown due to not properly destructed statement in addError
* Fixed indexer getting stuck after building caches because MessageFinishedParsing was interrupted
* removed Message::cancel() method and all related code
bug id = 105