test/helpers: add new functions
test/helpers: add new functions

Add the following functions:

* Create: wrapper around kubectl create
* WaitForServiceEndpoints: waits until the specified service contains the specified port
* GetEndpoints: gets specified endpoints from Kubernetes

Signed-off by: Ian Vernon <ian@cilium.io>

michi-covalent/cilium,scanf/cilium,cilium-team/cilium,scanf/cilium,tklauser/cilium,tklauser/cilium,eloycoto/cilium,cilium/cilium,eloycoto/cilium,scanf/cilium,eloycoto/cilium,tklauser/cilium,eloycoto/cilium,scanf/cilium,cilium/cilium,tklauser/cilium,scanf/cilium,michi-covalent/cilium,tklauser/cilium,eloycoto/cilium,scanf/cilium,tgraf/cilium,scanf/cilium,cilium-team/cilium,tgraf/cilium,michi-covalent/cilium,tgraf/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,tgraf/cilium,eloycoto/cilium,cilium/cilium,tgraf/cilium,eloycoto/cilium,cilium/cilium,michi-covalent/cilium