Modify asdf info method to support comments in Roman data files

[stscijgbot-rstdms]

Issue RCAL-302 was created on JIRA by Perry Greenfield:

ASDF does not have a corresponding concept of the FITS header card comment for keywords since YAML comments are not generally meant to be read by YAML libraries. However, when schemas exist, the title attribute for a property can be interpreted as an analog to the FITS keyword comment. This ticket is to extract that string and print it out on the info display so users can see the corresponding short description for what the attribute represents.

[stscijgbot-rstdms]

Comment by Nadia Dencheva on JIRA:

asdf-format/asdf#1138