Geo: Backport Exclusive Lease to 9.2
We have clients using Geo and getting hit by #1493 (closed) (see: https://gitlab.slack.com/archives/C32LCGC1H/p1495819652053705). While in !1789 (merged) we fixed the issue it was not part of 9.2 release because the approval was made after the deadline. The !1789 (merged) includes not only the fix but pays the technical debit introduced by the previous partial-solution.
What I'm proposing is that we migrate only the ExclusiveLease changes from the worker and include it in 9.2 stable, as a bugfix. This will not introduce schema changes nor UI / Interface changes.