QtIFW

Add objectnames and rename variables

We have decided to rename the archive as category. We already renamed
some of the classes etc. but some variable names were still with the old
name. Rename those to avoid confusion. Also add some object names so the
elements are available using control script.

Change-Id: I9ea50805a04acbd982eb742c906100afed86567a
Reviewed-by: Antti Kokko <antti.kokko@qt.io>