Fix the import statement order for qml files generated during import

Tooling is bit picky about the import statement order, so to ensure
things work properly, QtQuick import is generated before QtQuick3D
import. Also added QtQuick import generation for files that lacked it.

Task-number: QDS-2648
Change-Id: I601aa22e423e3ce89b9b07d0c1f5c34c72dcae52
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>
(cherry picked from commit 1717e915)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>