Bug 36837: Simplify XSLT and aid translatability

Bug 36837: Simplify XSLT and aid translatability

This patch makes the XSLT contain HTML tags instead of building them
from scratch with static attribute values. This made it awkward for
translators as CSS classes ended up being extracted for translation
purposes. Plus, there's no need to spend CPU cycles on static content
generation.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 48e39c1e5cea2db2c4e0951a6efcae7e611490fb)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>