Qml files used by Quick tests are not necessarily added to the
project file and therefore not fully handled by the QmlJS code
model / snapshot.
When adding qml files to a directory that is handled by the
code model these folders are not scanned again - we need to
enforce such a scan on AutoTest plugin's side.

Task-number: QTCREATORBUG-17805
Change-Id: Ie3d071a9aa03297d618648b06d52fb298c856d25
Reviewed-by: Marco Benelli <marco.benelli@qt.io>