Add timezone code next to timestamps in Analytics > Temporal Range

[emiliom]

Currently, timestamps shown in the "Show Analytics" panel under Summary > Temporal Range don't include a timezone code. A user can't tell if the timestamps are in the user's local time zone, in the time zone corresponding to the location observation, in UTC, or something else. Add a timezone code (PST, UTC, etc) after the timestamp string to eliminate this ambiguity.