migrate to PSR-4 namespace and use Composer in production#261

Draft

stklcode wants to merge 2 commits intodevelopfrom feature/psr4

+219-195

Commits on Mar 31, 2023

move classes to Statify namespace and configure PSR-4 autoloader
stklcode
committed

Commits on Apr 1, 2023

add vendor Prefix "Pluginkollektiv\" to namespace
stklcode
committed