* add CivArchive API
* Oops, missed committing this part when I updated codebase to latest version
* Adjust API for version fetching and solve the broken API (hash gives only files, not models - likely to be fixed but in the meantime...)
* add asyncio import to allow timeout cooldown
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Co-authored-by: Scruffy Nerf <Scruffynerf@duck.com>
- Added ModelMetadataProvider and CivitaiModelMetadataProvider for handling model metadata.
- Introduced SQLiteModelMetadataProvider for SQLite database integration.
- Created metadata_service.py to initialize and configure metadata providers.
- Updated CivitaiClient to register as a metadata provider.
- Refactored download_manager to use the new download_file method.
- Added SQL schema for models, model_versions, and model_files.
- Updated requirements.txt to include aiosqlite.
