Remove Threading from GUI Executor
Card transactions limit the issuing of APDUs to the current thread. At the moment, the executer runs actions in a seperate thread, so that it can abort the action. This behaviour prevents us from using transactions in a majority of use cases (e.g. EAC).
To resolve this issue, rewrite the executor to run actions in the same thread while keeping the possibility to cancel running actions.
It is also worth investingating whether actions really need to be cancellable. The action threading was introduced, because there was no possibility to cancel a running PACE call issued to a standard or comfort reader. Maybe it is acceptable to not cancel actions and rely on the user to do this on the reader itself.