[WRKLDS-1366] Descheduler: support evictions in background (descheduler refactoring)

Refactor the descheduler code base to allow a quick implementation of the proposal in https://github.com/kubernetes-sigs/descheduler/pull/1354.

DoD:

extend the PodEvictor with a ResetCounters so it can be initialized only once outside of the descheduling cycle: https://github.com/kubernetes-sigs/descheduler/pull/1447
generate UID for test pods: https://github.com/kubernetes-sigs/descheduler/pull/1454
PodEvictor: turn an exceeded limit into an error: https://github.com/kubernetes-sigs/descheduler/pull/1456
Thread-safe pod evictor: https://github.com/kubernetes-sigs/descheduler/pull/1458
Refactor descheduler_test.go: https://github.com/kubernetes-sigs/descheduler/pull/1459
e2e: TestRemoveDuplicates: limit the tested namespace: https://github.com/kubernetes-sigs/descheduler/pull/1471
e2e: TestTooManyRestarts: run descheduler as a whole instead of a single plugin: https://github.com/kubernetes-sigs/descheduler/pull/1472

is cloned by

WRKLDS-1420 Descheduler: support evictions in background (descheduler refactoring) II

There are no comments yet on this issue.