fix(deployer): handle cargo fetch without blocking logs, use async channels

[jonaro00]

Description of change

Fixes #1322 and some more

• Using blocking crossbeam channels was causing logs to be delayed. Switched over to tokio channels everywhere possible.
  • Initial logs from deployment now appear instantly, and one line is printed if the fetching takes time.
• Do a manual cargo fetch when building, and don't let metadata commands fetch. (this is causing CI fail, will look for compromise.)

How has this been tested? (if applicable)

Local run works as usual, with and without crates cached.
Deployment works for axum hello world with and without --no-test, with and without failing test.

[oddgrd]

Thanks for getting to the bottom of this! I left some questions.

[chesedo]

Looking good. Comments are mostly small