winrtrunner: simplify error handling

Introducing the macros CHECK_RESULT and CHECK_RESULT_FATAL
to condense the error checking code blocks into one line each.

Change-Id: I485d21534c44f75d23e465ae6a6f048b6f255c52
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
winrtrunner: install missing dependencies

On install, winrtrunner will check the app's dependencies,
look for them in the directory of the extension SDKs and
install them automatically for the current user.

Task-number: QTBUG-37598
Change-Id: I5639491ee47af16618279245eed4dd94e61f58f9
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>