Fix EZP-22128: Change license & copyright info to be in root of project

(cherry picked from commit c106d0b73b75752f6ef84cf08bd6bbea96cb81b8)
Fix EZP-22128: Update Copyright info in extension.xml

(cherry picked from commit 055668807ee2a4e9225c167edab96d1ff7e8e452)
Fix EZP-22128: Re add original external copyright
(cherry picked from commit 9b025d9c2d74c3f3fafe99b45f3afe56f96d9539)