QtIFW

move ts targets to a separate project file

that makes it possible to update the templates even if the ifw itself
cannot be built (e.g., due to using a -no-widgets qt build).

Change-Id: Ie170e6524dbed40f6c8b837e35af6b45a1c2d2dd
Reviewed-by: Katja Marttila <katja.marttila@qt.io>