Show .qml files being referenced in .qrc files in the project tree

Executable files (.qml, .js) that are referenced via .qrc files should show up in the Project Tree, and be part of the code model.

We've been changing quite some Qt Quick examples to work with .qrc files lately. This has (in contrast to file-by-file deployment) the advantage that it doesn't require any qmake magic to also work in shadow build, .app deployment cases. However, the files do not show up as being part of the 'project' in Qt Creator. Ideally they'd be added, pretty much like .e.g .qml files that are deployed via INSTALL qmake rules are shown in the project.