Bug 11322: fix XSS bug in purchase suggestions - OPAC

Bug 11322: fix XSS bug in purchase suggestions - OPAC

1/ Add a suggestion in the opac, with lots of html
2/ View that suggestion in the OPAC, note the html is rendering
3/ Apply the patch
4/ Test again, in prog and bootstrap, no more rendered html

Signed-off-by: David Cook <dcook@prosentient.com.au>
Works as described.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 90f3b84def924dcc76719c01d75aa09241c92f8e)
Signed-off-by: Fridolin SOMERS <fridolin.somers@biblibre.com>