This change adds a generic version of the various workqueue types while
retaining compatibility for the existing exported symbols and constructors.
The generic variants are prefixed with `Typed` and the existing ones are
marked as deprecated to nudge people to transition without breaking
them.
Kubernetes-commit: 0c7370bb851c15825d30a516722139ccccca0cfc
The default queue implementation is mostly FIFO and it is not
exchangeable unless we implement the whole `workqueue.Interface` which
is less desirable as we have to duplicate a lot of code. There was one
attempt done in [kubernetes/kubernetes#109349][1] which tried to
implement a priority queue. That is really useful and [knative/pkg][2]
implemented something called two-lane-queue. While two lane queue is
great, but isn't perfect since a full slow queue can still slow down
items in fast queue.
This change proposes a swappable queue implementation while not adding
extra maintenance effort in kubernetes community. We are happy to
maintain our own queue implementation (similar to two-lane-queue) in
downstream.
[1]: https://github.com/kubernetes/kubernetes/pull/109349
[2]: https://github.com/knative/pkg/blob/main/controller/two_lane_queue.go
Kubernetes-commit: 87b4279e07349b3c68f16f69a349a02bddd12f25
