iotests: Make 144 deterministic again

iotests: Make 144 deterministic again

Since commit effd60c8 changed how QMP commands are processed, the order
of the block-commit return value and job events in iotests 144 wasn't
fixed and more and caused the test to fail intermittently.

Change the test to cache events first and then print them in a
predefined order.

Waiting three times for JOB_STATUS_CHANGE is a bit uglier than just
waiting for the JOB_STATUS_CHANGE that has "status": "ready", but the
tooling we have doesn't seem to allow the latter easily.

Fixes: effd60c878176bcaf97fa7ce2b12d04bb8ead6f7
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2126
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20240209173103.239994-1-kwolf@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>