Copy the packages into the build directory so they can be found without installign

Summary: Fixes the execution of tests when not installed

Test Plan: Removed the installed effect and testTranslucency

Reviewers: KWin, zzag

Reviewed By: KWin, zzag

Subscribers: zzag, kwin

Tags: KWin

Differential Revision: https://phabricator.kde.org/D22490