additional fix to #17984 (MathML attrs in PDF) (#18508)
Link to issue number:
Closes #17984 (again)
Summary of the issue:
Acrobat's interface doesn't allow code to get all the attributes; they need to be queried individually. I missed an attribute that is relevant for some braille math codes.
Description of user facing changes:
Affects some math braille code output, such as Nemeth code.
Description of developer facing changes:
None.
Description of development approach:
Added some more cases for other math elements
