Add Fanout and Status 406 metrics

apiadded

The following new metrics have been added: status_406, fanout_req_header_bytes, fanout_req_body_bytes, fanout_resp_header_bytes, fanout_resp_body_bytes, fanout_bereq_header_bytes, fanout_bereq_body_bytes, fanout_beresp_header_bytes, fanout_beresp_body_bytes, and fanout_conn_time_ms.

Prior change: Add created_at fields to Secret Store API endpoint responses

Following change: New validation errors when creating automation token