Issue #3494780 by kristiaanvandeneynde: Re-evaluate Entity API dependency and drop dead code

composer.json

group.info.yml

group.routing.yml

group.services.yml

modules/gnode/tests/src/Kernel/GroupNodeConfigTest.php

src/Entity/Access/GroupAccessControlHandler.php

src/Entity/Access/QueryAccessHandlerBase.php

src/Entity/Controller/GroupRevisionOverviewController.php

src/Entity/Form/GroupRevisionDeleteForm.php

src/Entity/Form/GroupRevisionRevertForm.php

src/Entity/Group.php

src/Entity/Routing/GroupRevisionRouteSubscriber.php

tests/src/Kernel/GroupConfigTest.php

tests/src/Kernel/GroupKernelTestBase.php

tests/src/Kernel/RevisionUiAccessTest.php

tests/src/Kernel/Views/GroupViewsKernelTestBase.php