ockam_node improvements

[SanjoDeundiak]

1. Make crate-public if possible:

   • NullWorker
   • Mailbox
   • NodeReplyResult
   • NodeError
   • NodeMessage
   • NodeReply

2. Make Executor functions crate-public

3. Refactor Cancel API to shorten calls like this

   let m = child_ctx.receive::<String>().await?.take().body();

   to this

   let m = child_ctx.receive::<String>().await?.body();

   Possible solution: merge cancel capability into Routed struct

4. Improve crate description

5. Mention route! macro in send and send_from_address functions description

6. Update forward function description

7. Update receive* functions description

8. Improve start_node description

9. Not counting tests: 7 TODOs, 2 FIXMEs, 11 unwraps, 2 panics, 1 expect

10. Fix cargo clippy warnings (there are 16)

11. Add usage examples for Context functions: address, aliases, new_context, start_worker, start_processor, stop_worker, stop_processor, stop, send, send_from_address, forward, receive*

[mrinalwadhwa]

Awesome! Thank you @SanjoDeundiak let's break this down into smaller sub issues.

[abhishekc-sharma]

Has this been broken down into smaller issues ? I can take on some of tasks if required.

[SanjoDeundiak]

Hey @abhishekc-sharma ! That would be great. Which tasks do you want to take?

[mrinalwadhwa]

Maybe this is a good place to start:

Fix cargo clippy warnings (there are 16)

Also note this PR from @spacekookie is making improvements to ockam_node
#2007

[abhishekc-sharma]

That seems like a good place to start @mrinalwadhwa . Will fix the cargo clippy warnings to start with.