Visualization of items with start and end time (time range) instead of just datetime

[santilland]

Currently the time control works with datetime based items. In order to better support STAC related items it would be great to extend this functionality to also allow for time ranges.

I propose to use the same logic for the objects passed to the time control either they contain:

• datetime or if datetime is null
• start_datetime and end_datetime

I see currently the timeControlValues expect to have date instead of datetime. It would be important to keep backwards compatibility? So maybe we use either date instead of datetime or we allow the use of both?

All times in STAC metadata should be in Coordinated Universal Time (UTC).

Timeline visualization

The idea is that the rectangle in the timeline will cover the whole specified time range from start_date to end_date.
Datetime only entries could either:

• have a minimum width, e.g. some pixels,
• or be represented by another symbol, e.g. circle instead of rectangle

Binning considerations

If bins are used, creating a separate issue for that here #2197 there are some visualization considerations, in summary:

• Datetime only entries would always be shown as part of a bin (fit always in a bin as they don't have size)
• timerange entries would only be inside of a bin if the bin is larger then the range, i.e. if the timerange fits completely inside the bin