Allow doc-view to open password-protected PDF files (bug#33684)

Allow doc-view to open password-protected PDF files (bug#33684)

* lisp/doc-view.el (doc-view-ghostscript-options): Removed "-sDEVICE"
option.
(doc-view-ghostscript-device): New customizable variable, passed as
"-sDEVICE" option to GhostScript.
(doc-view-pdf-password-protected-ghostscript-p): New function.
(doc-view-pdf->png-converter-ghostscript): Can now open
password-protected PDF files.
(doc-view-pdfdraw-program-subcommand): New function.
(doc-view-pdf-password-protected-pdfdraw-p): New function.
(doc-view-pdf->png-converter-mupdf): Can now open password-protected
PDF files.
* etc/NEWS: Mention new doc-view-mode feature.