Update citations adding support for exporting JSON formatted entries. (#314)

* Update citations adding support for exporting JSON formatted entries.

Minor updates to HTML formatting.  Changed Copy button from
individual buttons (Copy Text), (Copy HTML), to one Copy button
that copies the currently displayed window contents (text, HTML or
JSON).

* Updates based on Copilots suggestions.
I'm not fast enough on the mouse to test these edge cases.  But,
it looks like the handling should work.

* Cleanup based on feedback from Copilot

Focused on fixing Copilot identified issues.  Also, used AI to help
identify other potential edge cases and areas where the code
deviates from best practices.

The result was some cleanup of formatting issues in the page HTML and
rework of the modal dialog box to improve its behavior.  Some changes
better enable assistive technology (Screen Readers).  Updates to
javascript to improve handling of unexpected values and reduce
vulnerablities.

Author: stumbo