Support durations for events during playback

When using the playback mode to visual temporal events like Uber rides it'd be very nice for the rides to only be visible during the duration of the ride. We should allows specifying the start and end time of an event in the data and only show the data between the start and end time when doing a playback. This way we could see a real representation of the ride traffic (or any other temporal events).

As it stands the playback mode just looks for a timestamp inside a window and displays any data where the data's timestamp is in that window. This feature would change playback to respect a start and end time for data that comes from the data.

In a CSV-formatted data set, this could be represented with a `start_time` and an `end_time` column, or perhaps with a `start_time` and `duration` column. Of course, the hard part is getting playback to look at those columns and remove the data based on the columns.

Love the project, and thanks!

(also if you point me to the current playback code, I'll take a stab at this)

No file, test, or playback entry point is named in the issue. First locate the playback implementation and the data-ingestion path, then determine how start/end times or duration should be represented and applied during playback. Done means temporal events appear only within their specified intervals, with coverage for the chosen data format.

Written by the indexing model from the issue text.