org-export: New `org-export-get-parent-paragraph' function
* contrib/lisp/org-export.el (org-export-get-genealogy,
org-export-get-parent-paragraph): New functions.
(org-export-get-parent-headline, org-export-get-previous-element,
org-export-get-next-element): Internally use new function.
* EXPERIMENTAL/org-e-latex.el (org-e-latex-link--inline-image,
org-e-latex-link): Apply changes to topology functions.
This new function is especially useful since every object derives its
properties from those the containing paragraph.