Automatic merge from submit-queue (batch tested with PRs 44406, 41543, 44071, 44374, 44299)

Decouple remotecommand

Refactored unversioned/remotecommand to decouple it from undesirable dependencies:

- term package now is not required, and functionality required to resize terminal size can be plugged in directly in kubectl
- in order to remove dependency on kubelet package - constants from kubelet/server/remotecommand were moved to separate util package (pkg/util/remotecommand)
- remotecommand_test.go moved to pkg/client/tests module