Gateway.GetAddrUxOuts is awkward to use for multiple addresses, and leaks a JSON type into the gateway layer

Gateway.GetAddrUxOuts is awkward to use for multiple addresses, and leaks a JSON type into the gateway layer: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). 1. Can only query one address at a time.