feat(restore): implement file restore feature content deduplication and compression

[masiedu4]

This pull request introduces significant changes to the core functionality of the project, particularly focusing on content storage, restoration, and file state management. The most important changes include adding a new ContentStore struct for handling file storage and retrieval, implementing restoration logic, and enhancing the FileState struct with additional traits.

Content Storage and Management:

• Added ContentStore struct in src/core/content.rs to handle file storage, retrieval, compression, and verification. This includes methods like store_file, retrieve_file, cleanup, and verify_content.
• Updated src/core/snapshot.rs to integrate ContentStore for managing file states and storing file hashes. [1] [2] [3]

Restoration Functionality:

• Introduced src/core/restore.rs to handle restoration processes, including functions like perform_restore, has_uncommitted_changes, has_available_space, validate_permissions, and generate_restore_report.
• Added RestoreReport struct in src/core/models.rs to encapsulate details about added, modified, deleted, and unchanged files during restoration.

Enhancements to Models:

• Enhanced FileState struct in src/core/models.rs by adding Clone and PartialEq traits to support comparison and cloning.

Dependency Updates:

• Added new dependencies sysinfo and zstd in Cargo.toml to support system information retrieval and compression functionalities.

Module Integration:

• Updated src/core/mod.rs to include new modules restore and content.