Allow Sidekiq job compression without limiting
This allows compressing jobs in compression mode, without having to specify a threshold at which to raise an error.
With this, setting a the limit threshold to 0 in compression mode, will result in the jobs being compressed without anything else.
As a result of this, we will be able to enable the compression mode by default for self-managed installations, who can all benefit from this. But without having to enforce the same limits we do on GitLab.com
The default for the limiter at this stage remains the tracking mode, so none of this applies to self-managed instances yet. On GitLab.com we have specified a limit.
This is part of gitlab-com/gl-infra/scalability#1177 (closed), a prerequisite to !68982 (merged)
Edited by Bob Van Landuyt