BUG: Prevent out of sync market closes in performance tracker.

In situations where the performance tracker has been reset or patched
to handle state juggling with warming up live data, the `market_close`
member of the performance tracker could end up out of sync with the
current algo time as determined by the

The symptom was dividends never triggering, because the end of day
checks would not match the current time.

Fix by having the tradesimulation loop be responsible, in minute/minute
mode, for advancing the market close and passing that value to the
performance tracker, instead of having the market close advanced by
the performance tracker as well.
ENH: Remove dependency on benchmark for trading day calendar.

Instead of the benchmarks' index, use the trading calendar to
populate the environment's trading days.

Remove `extra_date` field, since unlike the benchmarks list,
the trading calendar can generate future dates, so dates for
current day trading do not need to be appended.

Motivations:
- The source for the open and close/early close calendar and the
  trading day calendar is now the same, which should help prevent
  potential issues due to misalignment.
- Allows configurations where the benchmark is provided as a
  generator based data source to need to supply a second benchmark
  list just to populate dates.