nodediscovery: add LocalNode method
nodediscovery: add LocalNode method

This method will be used in a subsequent commit to retrieve a copy of
the localNode object stored in the nodeDiscovery one.

Signed-off-by: Gilberto Bertin <a93f35d43382e9739cc1b4df252abaa0d7c5c77f@cilium.io>

cilium/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium