Add logs for time ranges within the files

[greglucas]

It would be helpful for debugging things to know what time range is in data files when we are in the post-processing steps. There have been a few times where people have reached out to say there is only half the days worth of data in the files, so it might be helpful to put the range down to make it explicit without needing to open up the files.

Maybe in the write_cdf() routine?

imap_processing/imap_processing/cdf/utils.py

Line 76 in e0016b3

def write_cdf(

if "epoch" in ds:
    start, end = ds["epoch"].data[[0, -1]]
    # convert epoch to human readable time
    logger.info(f"Time range of dataset (name?): ({start}, {end})")