Update framework test generator to support TF/TFL conv3d.

Add a new attribute `rank` to indicate the testing dimension range of
input tensor. Also fix a minor bug in the existing conv3d simulation.
And relax rescale operator in the reference model to support 5-D input.

Change-Id: Ib42fe513831dc83eb7f9af07e011787a6c752704
Signed-off-by: TatWai Chong <tatwai.chong@arm.com>