[FEAT] Output JDaviz graphics (Export) to publication quality pdf

[larrybradley]

Jdaviz component

Other (explain below)

What is the problem this feature will solve?

This is a feature request from @kaya4me2 (spacetelescope/aas245_da_workshop#30) that we got from the AAS 245 workshop:

"Have a request that the developers consider adding an output in the EXPORT the ability to create a high resolution (dpi => 300) pdf file that is of publication quality for journals. Right now the options are only low resolution *.png, or *.svg files (to local machine working directory).

Thanks. Chick"

Describe the desired outcome

see above

Additional context

No response