API: Add new Get Inbound User (#3644)

* Add GetInboundUser in proto

* Add get user logic for all existing inbounds

* Add inbounduser command

* Add option to get all users

* Fix shadowsocks2022 config

* Fix init users in shadowsocks2022

* Fix copy

* Add inbound user count command

This api costs much less than get inbound user, could be useful in some case

* Update from latest main