reorg sciml simulate

[mwdchang]

Summary

This covers the Simulate operators, Calibrate and Ensemble will be dealt with in different PRs.

There are two themes to the PR here

• Reorganization and simplification of the operator logic, we no longer need to support multiple concurrent simulations within the same operator, and this means we can simplify state management and remove logic that never quite worked completely.
• Enable a preview on the workflow within the operator node, the nodes will poll and update in a similar manner as the drilldown.

[YohannParis]

This will work if the workflow is still running on the background when the drilldown is open, but if in the future we open those drilldowns in their own tab/window, we loose the Poller updates.

We have ClientEvent already available, listen to that with a Poller in the hmi-server? So now it doesn't matter where you are in the application.