Bug 19012: Note additional columns that are required during patron import

Bug 19012: Note additional columns that are required during patron import

This adds surname and cardnumber to the list of required columns on the
import tool screen and help page

To test:
Read the updated notes, verify it is true and understandable

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit 67f86868155725b3fec29d38a54e8c161dd72c78)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>