chore(access-node): rename and restructure files

access-node/access_node/CMakeLists.txt

...s-node/access_node/include/insite/arbor/arbor_endpoints.h

access-node/access_node/include/insite/config.h

access-node/access_node/include/insite/nest/endpoints.h

access-node/access_node/include/insite/nest/handler.h

access-node/access_node/include/insite/nest/json_strings.h

access-node/access_node/include/insite/nest/kernel_status.h

access-node/access_node/include/insite/nest/multimeter.h

...de/access_node/include/insite/nest/multimeter_container.h

...ss-node/access_node/include/insite/nest/nodecollections.h

...ss-node/access_node/include/insite/nest/spike_container.h

access-node/access_node/include/insite/nest/spikerecorders.h

access-node/access_node/include/insite/nest/spikes.h

access-node/access_node/include/insite/nest/version.h

access-node/access_node/include/insite/opcodes.h

access-node/access_node/include/insite/params.h.bak

...ss-node/access_node/include/insite/query_string_builder.h

access-node/access_node/include/insite/spikedetector.h

access-node/access_node/include/insite/tvb/endpoints.h

access-node/access_node/include/insite/tvb/handler.h