Resolve potential datetime schema concatenation challenges

There may be datetime schema concatenation challenges which need to be resolved in order to join data with related fields.

> I suspect the datetime is the column `Metadata_AbsTime` in the `Image.csv` files

```sh
csvcut -c Metadata_AbsTime ~/Downloads/Image.csv
# Metadata_AbsTime
# 2021-05-02T16:07:21.633-04:00
```
> It's ok to parse these as text, if that makes things easier (in the short term)

_Originally posted by @shntnu in https://github.com/cytomining/CytoTable/issues/29#issuecomment-1421582451_