qemu-iotests: test larger clusters sizes on qcow2

qemu-iotests: test larger clusters sizes on qcow2

This patch adds test case 023 which tests some more cluster sizes. For
anythinger larger than 4k clusters we can't use requests that are l2_size or
more (128k for 1k clusters, 2 MB for 4k clusters, 512 MB for 64k clusters).
Therefore one of the common.pattern cases is changed and needs new expected
results for some old test cases.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>