Add mechanism to check the regions parameter for AWS buckets

[fdalmaup]

Affected integration
AWS

Description

Since #22514, the AWS integration tests are generating their resources to test the module's behavior. Each launched test involving an S3 bucket creates the bucket, populates it with the corresponding logs, and at the end deletes the resources. For the --regions parameter, a test case involves requesting the logs for an unexistent region (us-fake-1) which in a normal module execution treats the parameter as a part of the log path and would return the following:

/var/ossec/wodles/aws/aws-s3 -b test-bucket -t config -s 2022-JAN-31 -p dev -d2 --regions us-fake-1
DEBUG: +++ Debug mode on - Level: 2
DEBUG: Generating default configuration for retries: mode standard - max_attempts 10
DEBUG: +++ Table does not exist; create
DEBUG: +++ Working on 123456789123 - us-fake-1
DEBUG: +++ Marker: AWSLogs/123456789123/Config/us-fake-1/2022/1/31
DEBUG: +++ No logs to process in bucket: 123456789123/us-fake-1
DEBUG: +++ DB Maintenance

Nevertheless, since the test builds up the bucket entirely and the region is not part of the available AWS regions, it fails and does not find the mentioned fake region.

The objective of the present issue is to modify the bucket's behavior to check the input --regions parameter and in case a nonexistent region is passed, to display a warning message that the region does not exist.

Tasks

• Test in a manager.
• Test in an agent.
• Unit tests without failures. Updated if there are any relevant changes.
• Integration tests without failures. Updated if there are any relevant changes.
• Update the documentation if necessary.
• Add entry to the changelog if necessary.