First 100 commits and refacto of DB-Func.php (#6104)

* doc(release note) : Add empty release note for the 2.8.19

* Security Fix : SQL injections on Ldap Parameters page

* update Centreon web 2.8.6 release notes

* improve documentations

* fix(style):Using if instead of ternary

* fix(doc): Remove header

* fix(error): Missing }

* fix(query): Wrong utilisation of query

* fix(space):Missing space