Display UI binary error messages instead of silently exiting

[kaankabalak]

In the same vein as minio/console#3276, we would like to record the error when an error prevents ./minio-operator ui from running.

Fixes #1755

[kaankabalak]

Not sure why the decommission test timed out, I don't think it's related to the changes in the PR. If so, please do let me know 👍

[kaankabalak]

Not sure why the decommission test timed out, I don't think it's related to the changes in the PR. If so, please do let me know 👍

Seems like it's failing with the following error message this time around. I am merging the PR as this looks unrelated with the change.

------
 > [stage-1 5/5] COPY minio-operator /minio-operator:
------
Dockerfile:25
--------------------
  23 |     COPY LICENSE /licenses/LICENSE
  24 |     
  25 | >>> COPY minio-operator /minio-operator
  26 |     
  27 |     ENTRYPOINT ["/minio-operator"]
--------------------
ERROR: failed to solve: failed to compute cache key: failed to calculate checksum of ref 154f1920-6824-4aef-9297-2479406a90ff::lth5s48sbb66gtsen54z4gjd0: "/minio-operator": not found
/home/runner/work/operator/operator/testing/decommission-test.sh: cannot docker build -t minio/operator:noop .

[cesnietor]

thanks @kaankabalak !