Changes to Start Gateway

removed the request property dev_mode

removed the request property passphrase

the image request property default value changed from hummingbot/gateway:latest to hummingbot/gateway:development

added the optional property detail/items/ctx to the response with the 422 status

added the optional property detail/items/input to the response with the 422 status

the response's body type changed from object to no type for status 200

the response's body type changed from no type to object for status 200

endpoint added