remove complication from PresetTimeCallback

[oscardssmith]

Previously this code was doing some fairly weird stuff with the closures relying on indices being passed around in spooky ways. This was (I believe) intended as an optimization, but was confusing both me and the compiler, so I deleted it, and am replacing the in calls with insorted to make it faster.

Checklist

• Appropriate tests were added
• Any code changes were done in a way that does not break public API
• All documentation related to code changes were updated
• The new code follows the
  contributor guidelines, in particular the SciML Style Guide and
  COLPRAC.
• Any new documentation only uses public API

Additional context

Add any other context about the problem here.

[ChrisRackauckas]

No, it's not an optimization. It's a correctness thing. We need to subset after a thing is used to prevent double using the same tstop.

[oscardssmith]

added a check to the condition to make this only fire when the last dt brought us to a new t value.