Logging more output data

Currently during a simulation, `wrote 20000 events from trajectory {seed} to database` line is currently the only output logged.

For very long trajectories, it may be helpful to log more output data to enable easier tracking of simulation state.

Some helpful values to log are:
- Simulation time every 20,000 step
- Avg simulation time per step
- Anticipated total runtime

There is probably other useful information to log.

Start by locating the existing `wrote 20000 events from trajectory {seed} to database` log line and the simulation loop that emits it. Determine which timing values can be measured there, agree on the useful output and logging cadence, and consider how completion should be verified for long trajectories.

Written by the indexing model from the issue text.