Export back-ends: Use `org-export-get-reference'

Export back-ends: Use `org-export-get-reference'

* lisp/ox-beamer.el (org-beamer-link):
(org-beamer-plain-list):
(org-beamer-target):
(org-beamer-radio-target):

* lisp/ox-html.el (org-html--wrap-image):
(org-html--format-toc-headline):
(org-html-list-of-listings):
(org-html-list-of-tables):
(org-html-headline):
(org-html-inline-src-block):
(org-html-link):
(org-html-paragraph):
(org-html-section):
(org-html-radio-target):
(org-html-src-block):
(org-html-table):
(org-html-target):

* lisp/ox-latex.el (org-latex--caption/label-string):
(org-latex--wrap-label):
(org-latex-center-block):
(org-latex-drawer):
(org-latex-dynamic-block):
(org-latex-example-block):
(org-latex-fixed-width):
(org-latex-headline):
(org-latex-horizontal-rule):
(org-latex-latex-environment):
(org-latex-link):
(org-latex-plain-list):
(org-latex-quote-block):
(org-latex-radio-target):
(org-latex-target):
(org-latex-verse-block):

* lisp/ox-man.el (org-man-target):

* lisp/ox-md.el (org-md-headline):

* lisp/ox-odt.el (org-odt-format-headline--wrap):
(org-odt-headline):
(org-odt-format-label):
(org-odt-link--infer-description):
(org-odt-link):
(org-odt-radio-target):
(org-odt-target):

* lisp/ox-texinfo.el (org-texinfo--get-node):
(org-texinfo-radio-target):
(org-texinfo-target):

* contrib/lisp/ox-groff.el (org-groff-link):
(org-groff-radio-target):
(org-groff-target):

* contrib/lisp/ox-rss.el (org-rss-headline): Use
  `org-export-get-reference'.