endpoint: add updateRealizedState function
endpoint: add updateRealizedState function

Factor this out of `endpoint.regenerate()` and into its own function for
more maintainable, organized code. No functional change is intended.

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

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