* Add purge_tags to s3_bucket to allow preservation of existing tags
Adding `purge_tags` with default `True` to maintain existing behaviour
allows users to set it to `False` to preserve existing tags
Fixes#29366
* s3_bucket: Add further tests and improve tag handling further
Additional tests for purge_tags: False suggested some incorrect
logic and thus further improvements
Increase wait timeout on bucket deletion as it wasn't always completing
in the default 100 seconds
