Chunked storage type

[kirillt]

We have two storage implementations:

• File-based: all key-value pairs are stored in a single file.
• Folder-based: each key gets its individual file in a designated folder.

File-based storages tend to fail when dealing with map sizes nearing 10,000 entries, often resulting in slow, sometimes even flawed writing. On the other hand, folder-based storages must be inefficient when handling smaller values.

Chunked storage blends both methods: it utilizes a folder containing files, with each file holding multiple entries. We need a strategy to identify the chunks requiring updates after a storage model modification. The use of Merkle trees might be necessary for efficient synchronization of external updates.