Correct VM create date to fix the import in PostgreSQL

There is an incompatibility with PostgreSQL at PSE import time because of how we generate the create_date for view models involved in a PSE.

E.g.: We instantiate the SimulatorAdapterModel once and generate the create_date in the constructor. Then we use that SimulatorAdapterModel for each operation in PSE and write it to H5 with the same create_date for all operations. At import time, we sort the operations by this create_date, and it will be the same for all operations in a PSE. The problem is that BurstConfiguration should be imported before any of the PSE results. As we keep it only in the first operation folder, we should ensure that one is imported first.

My first thought is to generate the create_date at H5 write-time.