Changes to Create a routine — scheduled agent execution [write]

added the new optional header request parameter Idempotency-Key

added the new optional request property initial_events/items/interaction_mode

added the new optional request property target/oneOf[subschema #1]/reuse_session

added the optional property effective_deliver_to to the response with the 201 status

added the optional property error/request_id to the response with the default status

the response property error became required for the status default

the response property error/code became required for the status default

the response property error/message became required for the status default