LIFECYCLE - fix issue with delete only 3K objects a day

[jackyalbo]

Explain the changes

1. delete_multiple_objects_by_filter will return the number of objects deleted
2. lifecycle will run every 5 minutes if any of its rules has deleted the max objects it can (1K - meaning he can delete more and we shouldn't wait to the next cycle)

Issues: Fixed #xxx / Gap #xxx

1. Fixed https://bugzilla.redhat.com/show_bug.cgi?id=2279964

Testing Instructions:

1. create more than 3K of objects on a bucket (let's say 3.5K)
2. set this lifecycle rule:

{
    "Rules": [{
          "Expiration": {
                "Days": 1
            },
            "ID": "data-expire-withoutprefix",
            "Filter": {
                "Prefix": ""
            },
            "Status": "Enabled"
        }
    ]
}

3. wait till LIFECYCLE runs a day after - see that it deleted all the objects and not just 1K object every 8 hours.

• Doc added/updated
• Tests added

[liranmauda]

LGTM, just some small comments.