460 etl timezone

[kjlippold]

• Updated parse_series_to_utc to preserve timestamp timezones when provided, and handle mixed tz-aware/tz-naive timeseries.
• Added missing argument to ETL CSVTransformer.

[daniel-slaugh]

I ran this locally and the happy path works as expected.

I found one nitpick bug: If the timezone information is hour only like 2024-01-01T12:00:00-07, timestamp.py will crash the batch since the timestamp is misclassified as naive, tries to localize, and throws a TypeError. I recommend adding support for this since we'll probably have a user at some point that uses this timestamp format.