Newer scanner support

[melissalinkert]

This is one approach to fixing #40, but has not yet been tested on real data.
This is meant to fix the issue noted in #40, and subsequent issues on the same dataset.

With dateutil/dateutil#1252 still open, the %Y%m%d%H%M%S.%f%z format is not handled automatically. Separate cases for %Y%m%d%H%M%S.%f%z and %Y%m%d%H%M%S.%f appear to be necessary, as if I try a little test like this (using timestamps from #40 and #39 (comment)):

>>> new_date = "20241201163630.691045+0000"
>>> old_date = "20190612231659.000000"
>>> time_format = "%Y%m%d%H%M%S.%f%z"
>>> from datetime import datetime
>>> datetime.strptime(new_date, time_format)
datetime.datetime(2024, 12, 1, 16, 36, 30, 691045, tzinfo=datetime.timezone.utc)
>>> datetime.strptime(old_date, time_format)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\melissa\AppData\Local\Programs\Python\Python37\lib\_strptime.py", line 577, in _strptime_datetime
    tt, fraction, gmtoff_fraction = _strptime(data_string, format)
  File "C:\Users\melissa\AppData\Local\Programs\Python\Python37\lib\_strptime.py", line 359, in _strptime
    (data_string, format))
ValueError: time data '20190612231659.000000' does not match format '%Y%m%d%H%M%S.%f%z'

[sbesson]

A few inline questions but overall, the changes make sense from a code review perspective.

Does https://github.com/glencoesoftware/isyntax2raw?tab=readme-ov-file#areas-to-improve need to be updated to document the new expectations in terms of support?

Generally, are we close to dropping support for iSyntax SDK 1.x since support for the new scanners including the 16 to 8 bit filter will only be available in the iSyntax SDK 2.x if I understand?

[melissalinkert]

Generally, are we close to dropping support for iSyntax SDK 1.x since support for the new scanners including the 16 to 8 bit filter will only be available in the iSyntax SDK 2.x if I understand?

Discussed a bit separately, but that's a little tricky. The changes here are meant to be specific to SDK v2, but we don't have a setup to test SDK v1 (nor are we likely to), so saying for sure that there is no impact on v1 use is difficult. I also wouldn't expect new scanner data to work with v1 at all. In the worst case, anyone who can't upgrade to v2 for whatever reason may need to stick with an older version of isyntax2raw.

[mabruce]

Works as expected on both an older and newer image, with and without --linear16to8.