WIP: Use cobra.ExecuteContext to cancel requests to the controller

cli/cmd/changeCommit.go

cli/cmd/changeConfirm.go

cli/cmd/changeGet.go

cli/cmd/changeList.go

cli/cmd/list.go

cli/cmd/login.go

cli/cmd/logout.go

cli/cmd/networkElementCreate.go

cli/cmd/networkElementList.go

cli/cmd/networkElementPathDelete.go

cli/cmd/networkElementPathGet.go

cli/cmd/networkElementPathGetIntended.go

cli/cmd/networkElementPathSet.go

cli/cmd/networkElementRemove.go

cli/cmd/networkElementShow.go

cli/cmd/networkElementSubscribe.go

cli/cmd/pluginList.go

cli/cmd/pndCreate.go

cli/cmd/pndGet.go

cli/cmd/pndList.go