feat(org): follow citations on +org/dwim-at-point

As discussed in #5290, pressing RET on citations (or citation
references) will now follow them.

Ref: #5290

modules/lang/org/autoload/org.el

@@ -150,6 +150,9 @@ If on a:
         (setq context (org-element-property :parent context)
               type (org-element-type context)))
       (pcase type
+        ((or `citation `citation-reference)
+         (org-cite-follow context arg))
+
         (`headline
          (cond ((memq (bound-and-true-p org-goto-map)
                       (current-active-maps))