Convert rerun to modern coding

We will first change initial rerun to "replicate( , simplify = FALSE )" to be in line with earlier intro of replicate and to use base R.  (Then show bind_rows)

When replicate_dfr exists in simhelpers, use that for much of the code and/or simply use the bundle_sim() method in simhelpers for clarity (and to avoid extra function writing that is unnecessary)
