envoy: Provide accessor functions for accesslog needs
envoy: Provide accessor functions for accesslog needs

This provides compatibility to pkg/proxy/accesslog types and is in preparation
for an overall proxy log cleanup

Signed-off-by: Thomas Graf <5f50a84c1fa3bcff146405017f36aec1a10a9e38@cilium.io>

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