feat(turbopack): Add basic compilation event support (#78785)
## Implement Compilation Events System for Turbopack
This PR adds a compilation events system to Turbopack that allows sending and subscribing to events during compilation. The system enables better communication of important information to users, such as filesystem performance warnings.
### What?
- Added a `CompilationEvent` trait in Turbo Tasks to standardize event messaging
- Implemented a broadcast-based event queue for distributing events to subscribers
- Created specific event types for diagnostics and slow filesystem detection
- Added JavaScript bindings to expose events to the Next.js frontend
### How?
- Created a new `message_queue.rs` module in turbo-tasks to handle event broadcasting
- Added methods to the TurboTasks manager to send and subscribe to compilation events
- Enhanced the filesystem benchmark to send detailed performance warnings through the new event system
