[report] Use start date for filtering

[lcfd]

Using start handles the “past midnight” sessions. It becomes more intuitive.

The only exception is when only end is passed.

  elif start is None and end is not None:
      records = [
          record
          for record in records
          if record.get("end", "") != ""
          and datetime.fromisoformat(record["end"]).date() == end.date()
      ]