Provide a way for qmake's OTHER_FILES to show up in IDEs

It seems that there is no equivalent to OTHER_FILES in our CMake build system yet:

#### Keys ignored in scope 1:.:.:fusion.pro:<TRUE>:
# OTHER_FILES = "$$PWD/../data/*.qml"
# TEMPLATE = "app"

So it's not possible to use Creator's locator to find QML files that belong to an auto test (but are only loaded automagically at runtime, so are otherwise not known by the build system).