The start of a monitor should automatically call constructor

[mojtaba-eshghie]

When a monitoring session starts, we should look for an activity with constructor id and execute it immediately. This is to enable effects of executing the constructor such as initialization of values or enabling other events to happen.

[mojtaba-eshghie]

This could alternatively be done merely via doing the first step (in DCR simulation) manually. We can do this for now for the replication package of the paper (add a customized simulation to the replication package).