Improve security for lib_xml

[mdeweerd]

Questions	Answers
Description?	Security fix for libxml. Call libxml_disable_entity_loader(true) and add LIBXML_NONET option for simplexml_load_string.
Type?	security fix
BC breaks?	no
Deprecations?	yes - libxml_disable_entity_loader not supported in reent PHP8.x - but protected with LIBXML_VERSION test
Fixed ticket?	None
Sponsor company	Applied in Dolibarr (not specifically sponsor company).
How to test?	Test multiple PHP versions, regression test.

[AureRita]

Hi @mdeweerd

Thank for your PR, This PR is too technical for me, ping @PrestaShop/tech-council, can someone please test this PR ?

Thanks

[matks]

Thank you @mdeweerd and sorry for late merge