Add event hook to do_step

Description

There are some cases where it is useful to stop the simulation when a condition is fulfilled.

Proposal

Add another stepper that is able to do a binary search of the condition to fullfill.

How to test the implementation?

Evaluate an step with a time-step higher than a known event to happen, and check that the step makes a pause approximately where the condition switches from one state to the other.

Related issues

See #