Add support for the multiple end events

[ira-halenok]

• Support multiple end events

[ira-halenok]

At the moment, if the BPM model contains two or more end events, the user will be notified that we do not support this setup. Temporal solution for the end user: create an XOR join-gateway with one end event. While we won't be able to specify different types of end events, we are able to at least exit the business process execution correctly rather than a failure.