add an arduino-router-cli for sending message to the router

[lucarin91]

It could be useful to have a CLI for sending messages to the router from the command line. We should at least support notify message, but we could potentially also support a call and provide.

I was thinking of an interface like the following:

arduino-router-cli notify <method_name> --int 6 --string "asdasd" --float 5

Parameter types are important in some bridge implementations (for instance, the sketch library), so we should have a way to make sure to compose the correct message arguments.

[SuMere]

+1 on this, could be useful to easily integrate this with the keybinder (news on this shortly).