refactor: split cli.rs into cloud.rs and enterprise.rs modules (#454)

* feat(redis-cloud): add tracing instrumentation to API client

- Add #[instrument] spans to all HTTP methods for structured tracing
- Add debug! logs for method/URL on each request
- Add trace! logs for request bodies and response status
- Follows same pattern as redis-enterprise client

This establishes a consistent tracing pattern across both API clients
for better observability and debugging.

Partial fix for #105

* refactor: split cli.rs into cloud.rs and enterprise.rs modules

- Extract Cloud enums to cli/cloud.rs (1477 lines)
- Extract Enterprise enums to cli/enterprise.rs (1389 lines)
- Keep shared types in cli/mod.rs (404 lines)
- Improves maintainability and navigation

Closes #440

Author: joshrotenberg