Review and update Gcloud unit tests

[CarlosRS9]

Related issue
#13389

Description

In #13389 we have reviewed, updated, replaced existing unit tests for our gcloud module while adding new ones to expand code coverage up to 99%. This is the actual coverage using the new unit tests:

---------- coverage: platform linux, python 3.10.4-final-0 -----------
Name                               Stmts   Miss  Cover   Missing
----------------------------------------------------------------
gcloud/buckets/access_logs.py         16      0   100%
gcloud/buckets/bucket.py             128      2    98%   26-27
gcloud/exceptions.py                  23      0   100%
gcloud/gcloud.py                      68      1    99%   111
gcloud/integration.py                 36      1    97%   38
gcloud/pubsub/subscriber.py           60      2    97%   21-22
gcloud/tests/test_bucket.py          225      0   100%
gcloud/tests/test_gcloud.py           35      0   100%
gcloud/tests/test_integration.py      53      0   100%
gcloud/tests/test_subscriber.py       73      0   100%
gcloud/tests/test_tools.py            34      0   100%
gcloud/tools.py                       41      0   100%
----------------------------------------------------------------
TOTAL                                792      6    99%

To achieve this it was necessary to replace existing unit tests and create them from start. However, it has not been possible to create a tools.py auxiliary module for the unit tests due to the problem of the wodle folder not being an installable python package. Once #12874 is addressed, it will be possible to do so, further optimising the design of these unit tests.

The extensive code review has resulted in several optimizations, changes and removal of some parts of the code. Because of that, manual testing was necessary to ensure everything still works as expected.

[mcarmona99]

LGTM