Remove Workaround for Scheduler Import

Once SWM’s Scheduler is restructured so it can be imported via the standard Go mechanism, remove the workaround providing Scheduler’s API from within the controller (see #25 (closed)). To remove the workaround, perform the following steps:

• Change the replace statement in file “go.mod” to point to the proper repository.
• Check whether the project can build and the controller works as expected.
• Remove folder “internal/qos-scheduler” holding the copy of Scheduler’s API.