Many tests other than the camera/ tests use a camera. To increase code
sharing, move the base CameraTest class to the test library. The class
becomes a helper that doesn't inherit from Test anymore (to avoid
diamond inheritance issues when more such helpers will exist).
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
