Inconsistent UDP shell support across network stacks — request for a generic udp command

Inconsistent UDP shell support across network stacks — request for a generic udp command: a task in LegoFlow-SWE (Harbor dataset). When applications use the sock udp abstraction for UDP communication, the shell experience depends on which network stack is active. With GNRC, a shell cmd gnrc udp…

The task

When applications use the `sock_udp` abstraction for UDP communication, the shell experience depends on which network stack is active. With GNRC, a `shell_cmd_gnrc_udp` command exists, but it is not part of the default set and must be explicitly added by the application. With other stacks like lwIP no equivalent…

Part of Lego-X/LegoFlow-SWE.