handle app arguments if list is empty

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[lib] issues handling metatypes correctly, so rollback temporary

This partially reverts commit 47c9e2e1966ee69e6f077407667846512c44af44.

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
engine is the parent of the actor

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>