Use consistent datetime formatting in collection temporal extent

[anayeaye]

What

A new method was added to to veda-backend's pgstac schema to describe the maximum temporal range of items that have an end_datetime greater than the nominal datetime but the extents are recorded in a different format that what is used for datetime summaries. Update the max temporal extent method to align with the summaries formatting.

Where/how

temporal_extent_max sql

Should follow convention used in datetime summaries

min(datetime)::text --> to_char(min(datetime) at time zone 'Z', 'YYYY-MM-DD"T"HH24:MI:SS"Z"')
max(end_datetime)::text --> to_char(max(end_datetime) at time zone 'Z', 'YYYY-MM-DD"T"HH24:MI:SS"Z"'

AC

• Forward stac ingestor triggered updates to collection temporal extent use consistent UTC (Z) format