v0.3.0 - Trace live handler outputs from client

Adds:

• Handler tracing. Adds client trace command to get live logs from a handler or all handlers as they're happening.
• clippy linting and rustfmt tests in CI.

Changes:

• Bump package versions (showcasing vital upgrades):
  tokio == "1.6.1"
  tonic = "0.4.3"