Refactor dependencies and improve code structure

- Updated `reqwest` to disable default features and added `async-trait` dependency.
- Removed unused imports from `client.rs` to clean up the code.
- Removed `async_trait` attribute from `AuthenticatedDevice` and `AuthenticatedNode` in middleware files to simplify implementation.
- Fixed websocket message sending by converting JSON string to `Message::Text` directly.

Author: AdamLBS