Forwarding Service in command node

[mrinalwadhwa]

Currently

This works:

> ockam node create blue
> ockam forwarder create --node blue ROUTE_TO_ELIXIR_NODE

but it route to an elixir node running the our elixir forwarding service.

There is a Rust implementation of the forwarding service here
https://github.com/build-trust/ockam/blob/develop/implementations/rust/ockam/ockam/src/forwarder.rs

The client code needed to talk to either services in RemoteForwarder.

Here's an example of using it.
https://github.com/build-trust/ockam/tree/develop/documentation/use-cases/end-to-end-encryption-with-rust#rust-example

Desired

We would like to make this example work locally with ockam command

Along with the rename in #3193

The commands that would work after this is implemented would look like this:

> ockam node create alice
> ockam node create middle
> ockam node create bob

> ockam forwarder create --at /node/middle --for /node/bob
forwarding_address

# this would get a reply from bob
> ockam message send "hello" --from alice --to /node/middle/service/forwarding_address

This would require middle node to be running the forwarding service in its default services which are started here https://github.com/build-trust/ockam/blob/develop/implementations/rust/ockam/ockam_api/src/nodes/service.rs#L187

[mrinalwadhwa]

Closed in #3224