Simulator end of sim actions and exception handling

[mkorbel1]

Description & Motivation

This PR addresses a couple problems:

• Fixes a bug (End of simulation actions are not reset by Simulator.reset #556) where end of simulation actions were not cleared at Simulator.reset, causing them to get executed on the next simulation run
• Fixes a problem where the "end of simulation actions" were not executed if there was a simulator exception during the simulation. Since there sometimes "cleanup" types of activities registered at the end, it's important not to lose those.
  • Note: if a end of sim action throws an exception, other end of sim actions after it might not execute, nor the original simulator exception be thrown. This seems reasonable.

Related Issue(s)

Fix #556

Testing

Added new tests

Backwards-compatibility

Is this a breaking change that will not be backwards-compatible? If yes, how so?

Behavior will change, but this falls under "bug fix"

Documentation

Does the change require any updates to documentation? If so, where? Are they included?

No