Changes to Genai Spans Query

added the required property spans/items/main_agent_id to the response with the 200 status

added the required property spans/items/main_agent_name to the response with the 200 status

added the required property spans/items/response_time_to_first_chunk to the response with the 200 status

added the required property spans/items/workflow_name to the response with the 200 status

endpoint added