Add messages for `org-table-copy-region' and `org-copy-visible'

* lisp/org-table.el (org-table-copy-region):
* lisp/org.el (org-copy-visible): Add a message.

lisp/org-table.el

@@ -1865,7 +1865,8 @@ with `org-table-paste-rectangle'."
 	(forward-line))
       (set-marker end nil))
     (when cut (org-table-align))
-    (setq org-table-clip (nreverse region))))
+    (setq org-table-clip (nreverse region))
+    (message (substitute-command-keys "Cells in the region copied, use \\[org-table-paste-rectangle] to paste them in a table."))))
 
 ;;;###autoload
 (defun org-table-paste-rectangle ()

lisp/org.el

@@ -20008,7 +20008,8 @@ this numeric value."
       (let ((next (next-single-char-property-change beg 'invisible nil end)))
 	(setq result (concat result (buffer-substring beg next)))
 	(setq beg next)))
-    (kill-new result)))
+    (kill-new result)
+    (message "Visible strings have been copied to the kill ring.")))
 
 (defun org-copy-special ()
   "Copy region in table or copy current subtree.