refactor: new device group / device / parittion architecture

[MrCroxx]

Although the device framework on main has been restructured, it still cannot meet complex requirements.

Requirements:

• Multiple devices can be utilized (each device may be a directory or a raw block device).
• Each device has its own throttle and statistics.
• Different non-overlapping parts of each device can be used by different engines.

To address this complexity, foyer will restructure the device-related abstractions.

• Device Group: Aggregated devices that can be used by an engine, created by user.
• Device: A raw block device or a directory in a fs, or part of an existing device, created by user.
• Partition: An append-only continuous part of a device, created by engine in the init phase.

[MrCroxx]

This refactor can be too large and complex for the new version release. I prefer to hold this issue and impl it in future versions.