Request for VOTable code review

[Tom Donaldson]

Dear VOTable implementers and experts,

I've created a pull request on the Astropy VOTable reader/writer to correct a problem that has existed since Python 3 which, for FIELDs of datatype="char", stored values in the astropy Table as type bytes instead of str (e.g., b'myvalue' instead of 'myvalue').

Astropy and I would greatly appreciate if someone could have a look at this code, and enter a review here:  https://github.com/astropy/astropy/pull/9505

If Python is not your thing, thoughts on just the strategy behind the PR are also welcome (see this comment: https://github.com/astropy/astropy/pull/9505#issuecomment-567090773 ).

This PR raised for me a few issues in the VOTable spec regarding Unicode characters such as:
- Lack of direction on encoding
- Inconsistency on sizing between TABLEDATA and BINARY serializations

I will soon add that and other known issues to our new github repo for the VOTable spec, where they can be discussed further. 

Thanks for any help on this PR!

Tom