Overview:
This commit overhauls the Storage layer to set the foundation for a high-performance filtering system based on bitmap indexing. The refactoring introduces a more efficient data handling model and resolves critical issues that affected stability and performance.

Key Changes:
- Introduced the concept of 'WriteBatch' in the Storage interface to support efficient data operations.
- Removed the DB interface to eliminate excessive abstraction, making difficult the implementation of database-specific optimizations.
- Fixed the handling of byte arrays in Pebble's closer method to prevent data corruption. The Storage layer now ensures that data is parsed correctly before the Get operation is closed, eliminating the risk of random failures.
- Implemented batching for data writting from remote nodes, enhancing data consistency and speed.
- Restructured Mock objects into an internal package, restricting access to internals and eliminating the need for specific build tags.

Signed-off-by: Antonio Navarro Perez <antnavper@gmail.com>

Signed-off-by: Antonio Navarro Perez <antnavper@gmail.com>

Signed-off-by: Antonio Navarro Perez <antnavper@gmail.com>

Signed-off-by: Antonio Navarro Perez <antnavper@gmail.com>